| Author | Message | |||
     Stefan Morley Experienced User Username: myupctoys Post Number: 14 Registered: 7-2009 |
Hi all, Ive had my car for about a year. See Attached. Fixed a number of things in that time and am generally happy with it. Replaced the Gas springs, accumulators, one rear strut, tyres, brake pads, steering rack and sundry other little gremlins. One of the biggest joys is you fix something and it stays fixed unlike lesser beasts. That and the learning experience. There is one thing that keeps bugging me. At 2500>>2600 rpm the car feels very flat, acellerates beyond this but very flat in comparrison with idle to the 2500. I have progressively gone through a number of the systems. Like a vacuum switch that wasnt, a non return valve that returned, a sticky wastegate control solanoid and an corroded ignition amplifier. All these bits seem to work fine including the electrical signals they get. There must be something that I havnt looked at. Spark, that seems to be fine and advances roughly to what one expects, air well thats plentiful, and now I have fixed all the turbo related bits and the signals works as advertised air shouldnt be an issue, juice well it runs well at everything up to 2500. That 2500/2600 is quite a clean problem point. Fuel being an issue I would envisage the RPM issue would be a bit of pot luck. It is not rough, just flat. Would simply put it aside but one weeked I took it for a drive (couple of months ago) and it opened my eyes to what the car really can do. Something is intermittant, unfortunatly not mittant enough. Any thoughts Thanks Stefan  | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 15 Registered: 7-2009 |
Peoples, Thought I would add a couple of observations. BTW the Car is Bentley Turbo R 89 Chassis number but build is as per pre 89. For those interested the Mog is 1973 Turbo +8. Yes Turbo (factory fitted for Le Mans but never raced as race spec changed), not too many of them, from what I can gather 4. The problem doesnt appear to be throttle position as the throttle position to get to these RPM is quite different for neutral, 1st 2nd 3rd yet the issue is always distinct at 2500>>2600 rpm. Laterally thinking I dont think it would be the air volume sensor that controls the fuel delivery pressure, as the volume of air required again would be quite different from say neutral to 3rd so the metered air cone position would be quite different. If that hold true then the POT that measures this air volume should also follow suit. The timing changes and is very stable through the whole RPM range. Compression is good, cold engine 138psi +/-2psi, imagine that would improve on a warm engine but i dont feel like burning my fingers. In my mind the only consistant thing with these differeing engine loads, is the RPM. This would come from the sensor at the back of the engine. Which is detected by the ignition ECU and distributed to Boost and Fuel ECU. When the car did work as it should it felt like a cushion of power throught the whole rev range. At the moment it feels good to 2500 and then not much. On the flat its happy to keep acellerating but up a significant hill it almost feels like a brick wall. Stefan | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 16 Registered: 7-2009 |
Hi, One other thing that might help me and from what I have seen in a couple of other posts is to understand what the turbo boost does to manifold pressure in a known working Bentley setup. I played around with a Twin Turbo Toyota Supra, amazing japanese muscle out of quite a small engine. Anyway, boost means boost. The owner had modified it to pump 25 PSI. More than spec but thats his isssue. My point is the manifold pressure goes to 25PSI, ie about 11PSI above atmosphere. I read that the Bentley is supposed to cut out around 8 PSI. Ie a bit below atmosphere. It makes sense, with no boost the manifold will have an increased vacuum. So anything to get this pressure closer or even above atmosphere is in the right direction. I think I'm right in thinking atmosphere is 14psi roughly. I've measured the APT levels over rev ranges. Engine off but ignition on is 2V roughly. This would be 14psi or one atmosphere. Turn the engine on to idle, APT drops to .7V. To my mind assuming the sensor is reasonably linear this slightly less than half atmosphere, maybe about 5psi. What I have noticed is you increse the RPM, the boost doesnt really increase the pressure, the voltage stays about 0.7V, ie the manifold pressure remains at 5psi. If you didnt have the turbo working I think Im right in saying this pressure (ie voltage) would drop proportionally to the incresing rpm as the engine tries to suck more air in. The turbo working simply feeds more air to maintain this -ve pressure. Quick acelleration changes from idle shows a drop to about 0.2V which quickly reverts to the 0.7V, like wise quickly dropping the RPM shows a peak of about 2V then reverts to the 0.7V. Assume this is about the response time of the bypass valve in the plenum and the response of the wastegate. Problem is I have extrapolated this from observations on my car. Has anyone else done this on a car that works. I think this aspect of my car logically is working but in comparison to the Boost on the Supra the Bentley is not quite boost more maintaining a fixed manifold -ve pressure. Has anyone checked out what their manifold pressure is doing? The other thing that bugs me about the 2500>>2600 issue. The RPM seems to be the only constant at the moment, if the RPM is derived from the sensor at the back of the engine, and the ignition timing is a result of this sensor. If there where a problem with this then surely this would show up as a timing stability issue when using a timing light. Regards Stefan | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 384 Registered: 6-2006 |
Stefan, Boost pressure is ambient air pressure plus the turbo boost pressure. So in effect 0 psi plus the boost. Ambient pressure is variable because of weather conditions, height above sea level etc. Watch a barometer. MAP and MAF sensors work this out. Without a turbo or supercharger there is indeed a -ve manifold pressure but the charger increases the pressure so that the air is forced into the engine. But once again, it's ambient less the pressure drop. For your problem - Check all connections are clean and tight. Similar faults have been found by poor (low voltage) feeds to the ignition packs, engine ECU's etc. which become worse at certain revs. | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 17 Registered: 7-2009 |
Paul, Thanks. Will get myself a pressure gauge and monitor the manifold pressure. Trying to measure the APT is hardly giving me an absolute measure. Boost wise, trying to get my head around it. A normally aspirated car will allways be less than atmosphere at the manifold. For a Turbo car there needs to be a fair volume of air that needs to be moved before it becomes a +ve pressure with repect to atmosphere. Surely this -ve region is still defined as boost. Does the manual mean +ve pressure above atmosphere. Or +ve pressure above the normally aspirated -ve condition. With regards to connections, not sure there is that much left to check. Certainly found a couple of things in the process. If what you say is true about being above atmosphere then maybe my boost is not doing quite what I think. Pressure gauge is the first stop. Cheers Stefan | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1908 Registered: 4-2003 |
Stefan, I suggest that you search for this subject recently presented by Udo Hoffmüller on this Forum. He has a Turbo R with what sounds like the identical issue to yours. You may try sending him a private message.The last time I recall the subject appeared in a thread about headlamp sequence relays. Search for: Bistable relay instead of foot operat His has been a long-standing issue, but he had some leads in the last weeks and may have solved it already. RT. | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1910 Registered: 4-2003 |
Sorry, Search for Udo Hoffmüller or TurboR boost control failure I note that you have been a contributor to these and other threads on the subject. RT. | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 385 Registered: 6-2006 |
Boost wise, trying to get my head around it. A normally aspirated car will allways be less than atmosphere at the manifold. For a Turbo car there needs to be a fair volume of air that needs to be moved before it becomes a +ve pressure with repect to atmosphere. Surely this -ve region is still defined as boost. Does the manual mean +ve pressure above atmosphere. Or +ve pressure above the normally aspirated -ve condition. +ve above ambient pressure. At tickover with the throttle closed the pressure will be most -ve. The longer and smaller the air intake pipes and the air filter are the higher the vacuum will be. That's why nat asp racing cars have short trumpets, and no filters. At wide throttles and lower revs the vacuum is lowest , depending on intake restrictions. As Revs rise, the intake restrictions slow the flow and the vacuum will rise again. (Message edited by paul_yorke on 28 August 2009) | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1914 Registered: 4-2003 |
Paul, It all refers to nominal atmospheric pressure, 1013 Millibars. Under almost all conditions, except when driving hard, the manifold will be under a vacuum, -ve pressure as you name it. The pressure transdcers measure the pressure difference above or below 1013 millibars. Hence, the Turbo cars have a huge advantage at altitudes as the Turbo corrects the pressure to behave as if it were at sea-level. Unusually for a Turbo motor, the compression ratio on these cars is 8:1 as on the naturally-aspirated cousins. Hence there is no need nor possiblity for Turbo boost until you demand more torque than a naturally-aspirated Silver Spirit etc. Thats why many Turbo Rs have an inoperative Turbo system, and the owners dont even know. They just believe that the Turbo R is not a very fast car. Most other Turbo cars have maybe 5:1 compression ratios, and need the turbo boost far more regularly otherwise they are gutless. RHT. | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1915 Registered: 4-2003 |
ps: for Stefan. I suggest that you follow Udos lead. Fit a voltmeter or light bulb to the dump valve connection. You will then quickly see if the dump valve is functioning properly. Udo disconnected his dump valve circuit for a test, and it accelerated like a bat out of hell. You will then know if you have a dump valve control problem, the most common cause of loss of boost. If the dump valve itself is faulty, then it is easily and cheaply rebuilt. The unique dump valve system on these cars is the secret to thir amazing lack of Turbo lag. The turbo keeps spinning with no load until the dump valve redirects the air from recirculating to pressurising. RHT. | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 18 Registered: 7-2009 |
Thanks Paul and Richard, Okay happy with that; +ve pressure above atmosphere. Will get a pressure guage, but running on my assumption over the voltages I measure on the APT I dont think the turbo is doing much at all. Electrically I have fixed a couple of issues. Udo and myself have communicated on the forum. My Dump valve solanoid didnt work because the vacuum switch that is supposed to control it was faulty. Bought a new vacuum switch and the dump valve solanoid now operates electrically. Also the dump valve itself clicks now on rapid RPM increse as the manual states. Secondly I had a sticky wastegate solanoid since cleaned. Electrically that now works after a secondary issue was fixed. Secondary issue was power supply brown outs related to ignition amplifier corrosion problem dropping supply to the boost controller. Not quite sure how but once the amplifier was cleaned the problem went away. Anyway the wastegate solanoid now functions. Problem is it appears the boost is still not happening. Either my wastegate is permantly stuck open (seems unlikely given it would be more likely to be stuck shut through non use) or the dump valve is permanenly stuck despite now hearing a sound from it. The other thing I note in the manual is the dump valve itself can act as a relief valve, assume on its own. Maybe this isnt quite happening as it should allowing the dump to open. Have to figure out how to take the Intake elbow off to have a look. Should keep me occupied for the weekend. Cheers Stefan | |||
| Dr. Omar M. Shams Experienced User Username: omar Post Number: 39 Registered: 4-2009 |
Stefan, you are not alone on this matter. I am waiting for my 90 Turbo RL to come back from having the steering rack seals replaced before I do my invetsigations on the turbo system. These cars should fly like bullets, but mine (like yours) has a flat spot. I have toyed with the idea of replacing the ambient temperatur guage in the cockpit with a turbo boost guage in order to know what the manifold is seeing under all driving conditions. I may look into this in more detail. | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1916 Registered: 4-2003 |
The beloved steering rack again. See my articles. | |||
| Dr. Omar M. Shams Experienced User Username: omar Post Number: 40 Registered: 4-2009 |
Richard, where would I find these articles? I have had steering rack issues with every ShadowII/Wraith/Spirt/ Spur and Turbo RL that I have owned. I always put it down to the extreme heat where we live....... I am intrigued. can you please send a link? Thanks | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1919 Registered: 4-2003 |
Dr As I am in transit to Oz, I can only give you a start on the first article, the main one. Have a look at Tee-One here, and see a so-far success: http://rrtechnical.info/TeeOne/TO52.pdf I have had a new seal type on trial for a year now, a far better one than the original. I shall report the success or not ASAP, but am so far convinced. | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1921 Registered: 4-2003 |
Dr Also, if you look at Praeclarvm and Modern Lady around the time, you will see the whole bit, including the vital part on gapping the PTFEs. Your best rebuilders do not know about this. | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 19 Registered: 7-2009 |
Hi all, Well I got the Cast Elbow off, dump valve all looks fine and operates as advertised. Also tested the wastegate and that operates fine. Tested the fuel pot as well given the elbow was off. The mechancial fuel regulator vane moves freely as well. Physically I have checked each item related to the turbo. I will be testing the system with a pressure gauge in a week or so. Dont get me wrong the turbo is working, but only below the 2500>2600 and just above idle based on the vacuum switch. I have also gone through the process of disabling apsects of assorted parts of the system. None have been conclusive. Given I fixed the couple of parts that where faulty and now I am not getting anywhere looking at these parts the problem has to be elsewhere. Observation, the manual is not totally clear when trying to logically follow things. I made comment on negative pressure to make reference to pressure below atmosphere. Vacuum is not quite the right word even though its widely used in referece to what I called negative pressure. Semantics, but when you try to follow the manual one does get a bit lost. Started drawing up a diagram to make it clearer the interactions of all the parts. When done I will forward it to the forum. Steering rack wise mine started leaking from the left side on hard lock. (Right hand Drive car). Installed the reconditioned rack and functions fine. After pulling the old rack apart my two bobs worth is probably the biggest issue for these racks is the incredible lock on the cars. Combine that lock with verging on tyre scrubbing when at full lock and the forces on the center of the rack forcing the rack to writhe like a smake is proably the biggest killer on the ptfe bushes with the end result being the seals suffering. The only other car in my experince that has a comparable lock is the old VW beetles. Back to the topic at hand. I'm happy all the turbo related bits are functioning. I'm slowly convinced something beyond the turbo is causing an issue. I noticed something in the manual releated to the EHA in relation to the fuel mapping. Fuel mapping to the EHA ramps up to 2500 rpm. Then drops off quite markedly to the 4500rpm cutoff. Are my symptoms coincidence or more than that!!! They make reference to the turbo on the same map. Laterally thinking if this is the possible common thread then maybe the mapping is done under the pretext that at the lower RPM the engine needs slightly more fuel than the mechanical regulator can deal with hence the paralell EHA and when at the higher RPM there is sufficient boost pressure to force the mechanical fuel regulator into becoming the prime source and the EHA can back off with its supply.  It makes logical sense this is the intent of the mapping. If this is the source of the problem than my issue could be insufficanet fuel delivery at the higher volume or possible insufficient fuel delivery by the paralell mechanical regulator. I have a new high pressure fuel pump, and fuel filter. Howeever I havnt looked at the pump or filter in the Tank. Feel like a dog with a bone. But I am determined to solve it. Cheers Stefan | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 20 Registered: 7-2009 |
Hi, Just for interestes sake, compression ratio of Toyota Supras are somewhere in the order of 8.8:1 to 9.2:1 depending on the year. Add twin turbos and a bit of money and it beomes little wonder they can get towards 1000hp. Dont know how you control that sort of power in such a small car. Guess thats not the point. Stefan | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1922 Registered: 4-2003 |
Stefan, I am watching this topic very keenly. I do hope that you may write it all up for us: maybe for Tee-One Topics if Bill agrees ?? Semantics: agreed, not a vacuum. But semantics again: there is no such thing as negative pressure either. Itßs all relative huh ? Jokes aside, you are onto a subject seldom understood, one from which we will all presper once you succeed. RHT. | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 21 Registered: 7-2009 |
Hi, Been a little busy. Ordered a vacuum/pressure guage but it appears my boost is working from other tests. Still have an issue at 2500rpm... Since found a couple of things that might account. Though I'd share in case. By no means finished but it looks promising. My TPS wont switch to the full load map. Adjustment made no difference, contacts are stuffed. Ive ordered a new one. BTW they are made for SAAB and AUDI as well as Bentley and Rolls Royce. Bosch part number 0280120300. I got quoted $370 for a new one from factory, $49 from EBAY in the states. Anyway this is only a minor inconvience as when I defeat the TPS for full load map my base goes from 5.8ma to 16.5ma to the EHA as indicated in the manual. Thats good. But it doesnt follow the map as indicated earlier in this topic. Just doesnt change beyond that base change. All the sensors appear to function as per the attached pdf. The only ones that I have no idea on is the two extra wires not indicated in the manual. As I have a catylitic converter I assume they have an Oxygen sensor. Most other cars with oxygen sensors that fail put the ECU into a limp mode. If this is the case all I would be running on is the mechanical metering vane for fuel delivery given I see no changes in the EHA current beyong the base. Has anyone had experice with the Oxygen sesnors and the Bentley response to these being dead?
What surprises me is how well the car appears to be working despite. The work on the Turbo had to be done but thats not the full picture. Next stop is to figure out a source for the Oxygen sesnors. Hopefully there will be an aftermarket fit for them as well. Cheers Stefan | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 22 Registered: 7-2009 |
Hi, Slight correction. Pin 15 to the Fuel ECU is in fact the ground. See attached. Cant account for Pin2 being the same colour, be nice to assume its a ground as well. But I measured 10R there to chassis. Doesnt sound right for a ground. Could still be an Oxygen sensor, or a bad ground..... Why would the manual leave out the ground in the first place. Oh well. Stefan
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| Dr. Omar M. Shams Experienced User Username: omar Post Number: 41 Registered: 4-2009 |
Stefan, The TPS is available for $20 from http://www.saabdepot.com/cgi-bin/ppcart/ppcart.pl?cat&usedsaab900parts&Computers/Sensors Thanks or your updates and good luck - we are all watching this thread!!! Omar | |||
| Arthur F. Unregistered guest Posted From: 210.50.228.4 |
Forgot, You may need to remove the E.H.A to get access to this screw. (Message approved by admin) | |||
| Arthur F. Unregistered guest Posted From: 210.50.228.4 |
The E.H.A should have an adjustment screw to alter its working parameters (fuel enrichment). I saw a Mercedes 300CE with a flat spot issue cured by adjustment of the Electro Hydraulic Actuator. Hope this helps. (Message approved by admin) | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 23 Registered: 7-2009 |
Arthur, Dont think the EHA has any external user adjustment. Think its closed loop from the ECU. If I pulled it off and start changing that then the ECU might start playing up as and when I do get the rest of the parts working. The manual suggests, if I read it right, that once the idle speed is set the rest of the control happens based on the ECU and sensor information as a closed loop response. The issue I seem to have found is the EHA only has a base mixture current applied to it and nothing more. It does change current based on the TPS for the different load maps but follows none of the engine sensor information. Like its open loop. What is surprising is how much power there is despite things not as they should be, or the fact that it even runs at all. The next step is to find out what is causing the open loop response. Hopefully not a dead ECU. Doubt it as there are some things happening. TPS is a side issue at the moment. Good to know there is a cheaper source of TPS. Hopefully someone has experience with a Bentleys response to dead Oxygen sensors. Stefan | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 24 Registered: 7-2009 |
Hi, BTW, whilst I dont have the pressure gauge yet, the turbo related issue I started with in this thread is partially solved. The root cause of my issue was the Vacuum switch that controls the dump valve. I replaced it with a new one. The problem remained. Guess what; the new one was wired differently from the origional. This was from the factory at a ridiculous price. Hand made cars and all that. No matter a couple of crimps later and my APT measurements are showing boost. I say partially as I'm back to the point of having the boost controller turning off the wastegate solanoid. Least all the bits work. Something has to be telling the boost controller to open the wategate solanoid or the boost controller is playing up. First things first. Need to have the fuel system running in closed loop. Worry about the wategate later, maybe one will fix the other. Might seem like going around in circles but faults are being found and rectified. Cheers Stefan | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 25 Registered: 7-2009 |
Addition, The reason I hope the two are inter-related is the RPM range I loose power is 2500, roughly the RPM the wategate solanoid opens. Thats logical, you loose boost, you loose power. However thinking of it in another way and not totally sure how the three systems communicate their states electrically (Ignition, Boost and Fuel) other than there are some common wires. If the fault is the Fuel ECU (which I now now is not working correctly) tells the boost controller to reduce the manifold pressure to protect the engine. It is plausible, increse boost without increse in the fuel would make the mixture too lean and makes sense the ECU would try and prevent this. If this does hold true, it suggests that the fuel ECU is perfectly aware it is in closed loop mode otherwise it would aberrantly assume all was well and push more fuel in response to the increased air. Find that open part of the loop is key. Be nice if this older system had some form of self diagnostics like the later motronic. Stefan | |||
| Arthur F. Unregistered guest Posted From: 210.50.228.4 |
My understanding of the E.H.A function is that it does not alter base idle mixture (that is set elsewhere)but enrichens the mixture based on signals received from the oxygen sensor via the ECU.On a Mercedes the EHA has a tiny adjustment screw which if memory serves me correctly was on the underside requiring the EHA to be removed for adjustment in very small increments. (Message approved by david_gore) | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 399 Registered: 6-2006 |
"Dont think the EHA has any external user adjustment. Think its closed loop from the ECU. If I pulled it off and start changing that then the ECU might start playing up as and when I do get the rest of the parts working. The manual suggests, if I read it right, that once the idle speed is set the rest of the control happens based on the ECU and sensor information as a closed loop response." " that once the idle speed is set " The idle speed and mixture is set - the the EHA makes fine adjustments. Like many things - you are not supposed to touch or adjust them. The EHA mainly does small adjustments, but they can also block slightly putting the whole range out of kilter. I think there is a allen key? adjustment on it, behind a screew on the mounting face. Any adjustment is MINUTE and only recommended if the alternative is to bin it. They do respond well to be cleaned out though. Bad starting. (Running very rich. intermittent rough idling. ) Have you said what happens when running with it disconnected? I'm fairly sure that they don't give any feed back to the ECU. Also make sure you have the correct one for your car. Grey or Black. This can make them feel gutless. Have you measured plunger fuel pressure etc? And see if there's any variation at 2500 RPM (Message edited by paul_yorke on 04 September 2009) | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 33 Registered: 7-2009 |
Hi Paul, Seems I started a paralell thread. Divereted off looking at the pressure regulator and wrote up part number variations I found from bosch that didnt quite make sense. Since cleared up. My car starts easily, hot or cold, idles beautifully and never misses a beat till I get to the 2500rpm. In the other thread I mentioned fuel pressure tests which came up perfectly. The "plunger fuel pressure" you refer to, where is the tap for that on the distributor. If the pressure your referring to is the lower pressure chamber then that was done and came up at 78psi, both at idle and didnt budge at all when taken over 2500 rpm. Same for the primary pressure at 85Psi both right as per manual. I've learnt a lot but seems a bit more learning to be done  Stefan | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 34 Registered: 7-2009 |
Paul, Hart to tell due to ageing exactly what colour, it is sort of brown, gery black. But the Bosch part number on the EHA is 2437 020 010. No I havnt tried disconnecting the EHA and running it. Certainly will give it a try. Stefan | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 35 Registered: 7-2009 |
Hi, Electrically the only question mark I have come up with is measuring the Engine RPM output from the ignition ECU sourced from the engine position sensor. The Engine position sensor puts out 124 sine pulses and one large one (about twice the amplitude of the rest) presumably indicating TDC. From the Ignition ECU there is a square wave pulse twice per rev. I dont know if this is supposed to happen but it seems to coincided with firing on two of the coils and then a delay for the other two pots. Making 4 sparks per rev. The waveform looks like its intentional. But one pulse from the engine position sensor and two from the Ignition ECU is a quation mark. Probably fine. But could account for Boost controller opening early and stuffing with the fuel ECU. Wont ever know unless someone else uses a CRO triggering off the engine position sensor also looking at the ECU rpm output. Stefan | |||
| Udo Hoffmüller Experienced User Username: udo Post Number: 40 Registered: 2-2008 |
Dear Stefan, I did not read the whole thread in full. But it seams that discussing your problem one point is missing: It think, a loss of pour at 2.500 rpm (maybe it is really 2.400 rpm because of a certain incorrectness of the rev counter) means that the engine is knocking or that the boostECU decides that it is knocking altough it is not, and that happens if (even only one) knock sensor data is missing. Did you chek if the knock sensor data arrive correctly at the boostECU? Do the sensors work (test by knocking with a screw driver on the sensor connected to a voltmeter AC)? Did you drive with a voltmeter connected to the APT? You would be able to detect at which pressure exactly the power stops: 2.3 V means ambiant air pressure, every 0,25 V correspond to 100 mbar. The only connection between boostECU and engineECU is by the enginespeed signal (pin25). Every other data supplied to engineECU is meaningless for the boost management. Sorry if I repeated things already discussed, but the thread is already so long that I hoped to bring it back to the central problem. I got the impression that the discussion is already far away from the problem. On the other hand, forget my ideas if you think they are already discussed and out of interest. Regards - Udo (Message edited by udo on 04 September 2009) | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 36 Registered: 7-2009 |
Gday Udo, I agree this thread is getting a bit long. Around the point but still sort of on topic. Small diversion with fuel issues (reason for a new thread) I needed to make sure where addressed but still on the point. Power to the ground the end results is what we are all after. Firstly I totally disconnected the boost ECU. Forced the dump valve in to only boost mode only, the wastegate not to open and took it for a drive. Still a problem. Ignoring the fact that the boost is or isnt doing things disconnected and defeated I still have a problem. Therefore the issue should be coming from another circumstance. Not sure which thread I mentioned it on. But the only question mark electrically I have come up with is the two pulses per rev from the Ignition ECU (derived form the crank position sensor) that gets distributed to the Boost (temporarily disconnectd) and fuel ECU. However this is probaly a valid ECU output but cant be positive. Electrically the question in my mind is what is the common thread causing my issue (possibly yours) where the boost controller was taken out of the equation but was shared between the Fuel and Ignition ECU. The only ones I can land on are the Engine Speed indicator and the TPS. Fuel pressures (primary and lower chamber) checked, at both idle and over 2500 rpm, electrically most things checked, not too many questions left to ask; yet there is still an issue. Tomorrow I am going to take the catalytic convertor off and see what transpires there. Back pressure and all that. Should just be able to see look throught the convertor all being well. If not might take the car for a brief drive with no convertor and see what transpires. That should wake the neighbours. The other thing I will try that Paul suggested is disconnect the EHA and see what happens. Idle is a bit rough without the EHA connected but still idles. I've had too much amber lubrication to take it for a spin tonight. Tomorrow. Stefan | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 37 Registered: 7-2009 |
Udo, I'm not sure any of us knows where the symptoms will take us. The more I've pushed the boundaries the less like it seems like one symptom. You get a ford, I've got oil in the water. Well, youll get that occasionally........ Not that sort of symptom  My sense of humour couldnt help it. 4.1 litre Fords and all that. I finally have a boost pressure guage. Will let you know what transpires. Stefan | |||
| Udo Hoffmüller Experienced User Username: udo Post Number: 41 Registered: 2-2008 |
Stefan, first of all you must explain for me what you mean with "ignition ECU". From the manual I do not find any ECU like that. My car MCX 35566 (has no dump valve) has no "ignition ECU". The only thing it has is the "engine ECU". I hope this is the same. And if it is the same, then I would say that you are wrong: The only data lead from the engineECU to the boostECU is the enginespeed signal pin 25. The boostECU does not know what the crank position sensor tells the engineECU, there is no way for the boostECU to get this information. And what is the "fuel ECU"? What does this ECU do? Is my car so different? My car has no fuelECU, the fuel pump is simply monitored by the engineECU, i.e. the fuel pumps start for one second after ignition is switched on, then stop. When the engine arrives more then 35 rpm (or a similar value) the pumps start working again. That's it. No fuelECU. Are our car so very different??? If yes, we cannot compare our two cars. Regards - Udo | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 39 Registered: 7-2009 |
Udo, The Fuel and Ignition ECUs I'm referring to are two separate modules mounted just above the acellerator and brake pedals collectively known as KE2-Jetronic. The later Motronic combines these two systems into one unit, not sure where the module is mounted. There are also a couple of extra thing the Motronic does. Has two engine postiion senosrs, also has the O2 sensor just after the warm up catalytic convertor. Fuel pump wise similar end function. My car has the old system. Boost controller the same and most of the physical bits are the same. But the management system is different. Also a lot better desription for the newer one in the manual. The signal I am referring to is the engine position sensor mounted near the bell housing near the distributor. I measure this which goes into the the Ignition ECU, then the Ignition ECU changes this to a signal that pulses twice per engine rev. This signal gets distributed to the Fuel ECU and the Boost ECU. Presumably the motronic does something similar, monitors the engine postion sensor and feeds a modified version of that signal to the boost ECU. Stefan | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1927 Registered: 4-2003 |
The Motronic ECU is located underbonnet, under the plastic cover between the right hand suspension tower and the bulkhead. It was moved there as it is a hotter, colder, damper, drier, wetter and muddier environment, take zour pick, than insider the cabin. | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1928 Registered: 4-2003 |
ps: the KE-3 Motronic has the four segment sensor on the flywheel as its rotational position sender. The KE-2 Jetronic is completely different, and has the multi-toothed sensor with missing tooth as its rotational position sender. | |||
| Udo Hoffmüller Experienced User Username: udo Post Number: 43 Registered: 2-2008 |
Sorry, Stefan, I did not realize that your car has the Jetronic, but I was suspecting so because your description did not correspond to what I now from my car. Therefor my confusion. In my car I changed everything from sensors to engineECU which was faulty, but this did not do any effect to the turbo problem. As your system is different I will not meddle any longer - but read what happens. Regards - Udo | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 42 Registered: 7-2009 |
Udo, What country was your car origionally delivered to? BTW whilst the engine managment systems are different the boost controlers should be very similar, at least according to the manual. Stefan | |||
| Udo Hoffmüller Experienced User Username: udo Post Number: 44 Registered: 2-2008 |
The car is Monaco/France specification, but the buyer died before he could receive the car, so it was delivered in UK to his family, but LHD. The family did not want to stay with a LHD car in UK, so we were the car offered by Jack Barclay as we had been looking for one - our first TurboR had an accident, it was a total. So we own this car practically since new. Yes, the boostECUs should be the same, as the whole thing is Saab made (my boostECU shows even the Saab parts number). But my workshop manual and parts list starts at 1990, so I cannot verify as far to the parts number if they are really the same for cars before 1990. Regards - Udo (Message edited by udo on 06 September 2009) | |||
| Udo Hoffmüller Experienced User Username: udo Post Number: 45 Registered: 2-2008 |
Stefan, just two more questions to understand what you did and what you didn't: 1.) You drove the car while you had "totally disconnected the boost ECU". That means ...? The only point for the boostECU to govern the system is via the boost control solenoid. So you would have had to disconnect the solenoid and the ECU had no more possibility to affect the boost control, instead you put 10 or 12 V to the solenoid. Did you do so? And the dump valve (does not exist on later cars) was forced to stay closed? 2.) You told us the voltage at the APT. But this part of your report sounds strange to me: Engine off , but ignition on gives 2V, but 2V are not 14 psi (965 mbar) but correspond to only 12,2 psi (845 mbar). The correct voltage for ambient pressure is very close to 2,3 V ie 14,5 psi (1000 mbar). Everything else is wrong, I would say. A voltage of 2 V means a very very bad weather at only 12,2 psi (845 mbar). Are you sure the values you told us (more on the top end of the thread) are correct? Your car has only one APT for the engine and for the boostECU. My car has two APT, one for the engineECU and another seperate one for the boostECU. Both of them show the values I mention. I guess you know that you have to calculate P = 40V + 8 resp. V = p/40 -0,2 result in kPa (10 mbar, devide the result by 6.9 and you get psi) resp. Volt. So if you tell me that 2 V at the APT are shown at ambient air pressure - your APT is faulty. Ambient air pressure is about 14 psi under normal conditions, but that is close to 2,3 V! Calculation (the formula given by RR is using kPa): V = 100 kPa/40 -0,2 = 2,3. 100 kPa equals 14,5 psi. And more: As your car has only one APT for both systems (engine and booster), both of the systems are working with wrong data - always given the values you reported are what you have been shown by your voltmeter. And this would explain why you do not get power with or without booster connected or disconnected. Both systems receive the same wrong data. Therefor my question: Are you sure the values you told us are what the voltmeter showed? Best regards so far - Udo (Message edited by udo on 07 September 2009) (Message edited by udo on 07 September 2009) (Message edited by udo on 07 September 2009) | |||
| Dr. Omar M. Shams Experienced User Username: omar Post Number: 45 Registered: 4-2009 |
Stefan, Just to add to Udo's previous messages, and to assist with your troubleshooting...... I am not entirely sure if my symptoms are exactly the same as yours. My car has been in the garage for so long that I cannot remember exactly what my symptoms are like. I know that my car is not as powerful as I expected it to be. You, on the other hand, alreday have plenty of power, just not consistent over the whole speed range. I think I have limited or very little boost across the whole speed range. I will focus on the boost issue as soon as I get my car back from that damn steering rack leak issue. I have taken the rack apart 3 times and it still leaks... I am starting to lose it with this rack problem, but that is a separate issue for a different thread. Thanks Omar | |||
| Udo Hoffmüller Experienced User Username: udo Post Number: 47 Registered: 2-2008 |
Hello Omar! This is out of the theme of this thread - but did you talk to Richard Treacy as far to your leaking steering rack? I had the same problem, I have the fourth rack installed now, every time sent back to Introcar in London, every time a case of warranty. The reason is/was a wrongly handled seal inside the rack, but the problem should be completely sorted out, as far as I know in assistance of RT - my last rack has now done 40.000 km in the meantime without starting to leak again - okay, who knows how long it will last still!? And your turbo problem? You may have read about my own problem. Without engine speed signal the boost pressure is perfect - but I will have to sort out the problem and am suspecting the knock sensor insulation. I do not like to run the engine without the knocking of the engine monitored as consequence of the blocked engine speed signal. Regards - Udo | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 43 Registered: 7-2009 |
Udo, Answer your comments point wise. #1 I pulled the rubber pipe from the solanoid that goes to the wastegate and blocked it off. Also blocked the outlet of the solanoid to stop air leaking from the turbo. No pressure on the wastegate diaphram means wastegate stays closed (ie no exhaust bypass). Dump valve means I had no vacuum going to the dump valve diaphram meaning boost pressure can only go into the engine(no recirculation). Electrically I pulled the plug on the Boost controller to ensure nothing eletrically was upsetting the fuel and ignition ECU's. So I had permanent boost purley dependant on exhaust gas throughput and still had the flat point above 2500. The other point is by disabling the boost controller means if the boost controller was the root cause of my issue and it was disconnected, changes in what the boost controller had been doing would no longer be causing apparent changes in operation. Yet I still feel the issue. I would imagine the performace would change anyway but the problem point would shift or transition more smoothly. #2 2.182V, I had measured this previosly but didnt focus on it in my writeup as I had moved on from it. I live at about 600m so reading is a bit less than at sea level and its winter here. When I took this reading it was 1007 at sea level, so with 600m the level is probably about right. #3 I have two APT's Both voltages are very close to one another. My car is early 89, I call it 88 to stop confusion because in late 89 the Motronic systems where introduced. Omars comment, I dont know what to expect from a Bentley Turbo R. I love the engineering behind it and the main reason I dipped my toe in. I expect a car to meet its form and function and will ask no more from it. Handling wise, for a big car its incredible. Power wise I notice this issue at 2500rpm. Is it normal or isnt it. Some people say these cars are incredible, yet thats not what I find and presumably quite a number of others. How do you compare apples with apples when you only have one. Separate. I am focussing on the full load map and what that should mean to the Fuel ECU and what that does to the EHA. I have found a circuit and have found one inconsistanciy between the manual and what the circuit is. When I had the connector out for the boost ECU I seem to remember a similar inconstancy between the manual and what I had in my hand. I will also be opening up the boxes to confirm with a CRO electrically all signal are doing something internally. My line of thought is, firstly the EHA current not following the full load map from the fuel ECU. Second line of thought is why does the boost ECU open the wastegate valve (turn power off to the solanoid). Third is other than a couple of peripheral issues nothing core appears to be wrong other than these two differences. Stefan | |||
| Udo Hoffmüller Experienced User Username: udo Post Number: 48 Registered: 2-2008 |
Stefan, now I am more or less up to date with your investigations. And my solution was no solution :-( I understand that you really had the boostECU "out of service". And I see that you have 2.182 V at 600 m which is 953 mbar - that's realistic, especially if both of the APTs show the same value. One last question: Your boostECU turns the voltage at the solenoid to 0 V at which rpm? 2000? 2500? Can you exclude that reading of 2500 is 2400 in real because your rev counter is exact enough? I ask because as to the manual loss of boost pressure at 2.400 rpm means failure at a knock sensor, at 2.400 rpm the boost pressure is 200 mbar (basic pressure). My ECU cuts the power of the solenoid off at 2.000 rpm ie 0 mbar, the starting point of boost. Maximum pressure with power off at the solenoid is 200 mbar. Why didn't you run the car with the voltmeter connected to one of the APTs? You would know the pressure at any moment while driving. The fact that the solenoid is closed at close to 2.400 rpm could mean that the engine is knocking or the ECU believes so. Knocking can be caused by a hot running engine, ignition too early, aged lambda sonde ... many reasons. Are you sure, your ignitionECU is always using the correct ignition field (sorry, don't know the correct term)? The wrong ignition field under hard acceleration may cause knocking of the engine - and cutting off the power at the solenoid at basic pressure ie about 2.400 - 2.500 rpm. And also without boost pressure the wrong ignition field should cause loss of power. Do you exclude this possibility? Or is this idea nonsense? I am always fiddling about the number 2.500 - it is so close to the rpm where the solenoid cuts off the pressure in consequence of an inaudibly knocking engine - whatever maybe the reason for the sensors to detect knocking. And at the same time it must explain why you have loss of power at the same rpm without boostECU. The basic pressure of 200 mbar should always be present. Best regards - Udo | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 44 Registered: 7-2009 |
Udo, Did you find any existing holes suitable for wiring stuff into the cabin. Not really happy making the firewall look like swiss cheese. Really I need to run some of the tests whilst driving so we can compare notes. I assume you mean the wastegate solanoid. As close as I can measure changes to zero volts at 2150 rpm. Stefan | |||
| Udo Hoffmüller Experienced User Username: udo Post Number: 49 Registered: 2-2008 |
Stefan, change to 0 V at 2150 rpm is rather crazy - I do not know any conrete condition that would change at 2150 rpm, 2000 rpm - yes, 2400 rpm - yes, but 2150?? Very strange indeed. As far to the cables - I fitted two thin black cables in between the gap that is left by the mud guard, it is nearly unvisible. The gap between door an body is wide enough to enter the car. Regards - Udo | |||
| Udo Hoffmüller Experienced User Username: udo Post Number: 50 Registered: 2-2008 |
Ups - the pics have not been uploadad. Perhaps now ...   (Message edited by david_gore on 08 September 2009) | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 45 Registered: 7-2009 |
Udo, Thats a nice metallic blue. Will set something up tomorrow. There is a couple of things I want to monitor. I know the RPM is weird. I compared frequeny on a DMM with what my tacho is saying, multiplied by 60 and it seems spot on. Cheers Stefan | |||
| Omar M. Shams Experienced User Username: omar Post Number: 46 Registered: 4-2009 |
Udo, many thanks for your steering advice. I am waiting for RT to return from his trip to advise me on the rack issue. Stefan, sounds to me like you are not able to get enough fuel into your engine at 2500 rev/min. You did say something about your low pressure fuel pump. Are you able to monitor fuel pressure whilst driving? I know you have already measured it staionary but did you see what happens under load? if the pump cannot deliver due to wear and tear then you will only get symptoms of reduced performance at peak load. Another issue to consider is the possiblity of your new pump not being a good one!! Not all parts are perfect straight out of the box. I am convinced from what you have said that you do not have an air issue - strictly fuel. Good luck Omar | |||
| Udo Hoffmüller Frequent User Username: udo Post Number: 52 Registered: 2-2008 |
Dear Stefan, I did not want to show you the nice blue metallic colour of our car which is called royal blue metallic. What I wanted to show you are the black wires leading from the ATP (outside the pic) to the inner part of the car. Did you detect them? If you did not - well, that's what I wanted to show you, too, they are (nearly) invisible :-) But I have a problem with my english or yours: "I know the RPM is weird. I compared frequeny on a DMM with what my tacho is saying, multiplied by 60 and it seems spot on." What does that mean? Your tacho is telling you the correct rpm or is it telling you simply nonsense? Sorry, but as I never lived where english is been spoken, my knowledge of common speech is very limited. In spanish it would be much better for me :-) Best regards - Udo | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1940 Registered: 4-2003 |
A note: traditionally, electronic tachometers are driven by the ignition coil low tension. That means 4 pulses per revolution for a V8 with a single coil. Generally, manufacturers have stuck to the figures when grafting a conventional electronic tacho to an ECU. That means that at 1,000 RPM (revolutions per minute) on a conventional V8 petrol 4-stroke, the digital multimeter (DMM) will read a frequency of 1000x4/60 Hz = 67 Hz (Hz = Hertz = cycles, or pulses, per second). RHT. | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1942 Registered: 4-2003 |
Maybe we need a new thread for this one. You may read about the rack issue in Praeclarvm issue No. 4-06. August 2006. It is available to members on www.rroc.org.au under Club Magazine Archive. It also features in Modern Lady and elsewhere. These racks are of a very good basic design. However, the final execution leaves a little to be desired, and that is being kind. Unusually careful attention to detail seems to work in the best Royce tradition. Workmanship triumphs over design. You cannot successfully simply bang in a repair kit and hope for the best. With careful attention to the key details I outline, the racks seem much better. Introcar's subcontractor adopted all my recommendations, and has saved a fortune on warranty claims ever since. After a rash of failures with professionally-rebuilt ones on my Turbo R, I did the present one myself. The present rack has not needed a drop of top-up since 2005. The main thing that people do not know is how to gap the main PTFE bushes, but there are several other such essential points to note too. RHT. ps: to calibrate a V8 tacho, best is to use a signal generator. If you have none, simply use a 240VAC to 9VAC power adaptor and a bridge rectifier (4 diodes and no filter capacitor) as a 100Hz source. The bridge produces a 100Hz pulse wave 0V to +12V. You may use an old power adaptor from a mobile phone or whatever provided it is a transformer-type and not a switch-mode type. The small light newer ones are switch mode. Open it, and connect the bridge rectifier directly to the 9VAC output of the transformer. Connect the -ve of the rectifier bridge output to the chassis of the tacho and the +ve to the signal input of the tacho, and set the needle to 1500RPM. (Message edited by Richard Treacy on 08 September 2009) | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1943 Registered: 4-2003 |
You may read and download the rack article on: http://www.rrtechnical.info/rackextract.pdf Best is to subscribe to Praeclarvm of course. That supports the publishing of such articles. RHT. | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 46 Registered: 7-2009 |
Udo, Richard, The tacho derives its signal from one of the coil packs ignition pulse. The Bentley has two coil packs. Each coil pack fires twice per rev. Therefore 1500 rpm will give 1500pulses/60seconds/2coil packs or 12.5hz. My DMM has a resolution of .001hz Udo, yes I did see the wires and will do something similar. With regards to fuel pump, assume your talking the one in the fuel tank. When I replaced the high pressure one I did check that the in tank one worked. Maybe I should have pulled it out. Fuel wise, which my biggest question mark and follows on from your suggestion is the EHA. How do other people interpret the diagram on attached second sheet. The red line is what my car is doing. The chart is from one of the test flowcharts. The motronic has a similar sort of test. I dont see the 16.8ma indicated at the start of this chart change with so much of a flicker until I get to 2500 where it start dropping. This fits with the fuel hypothesis. It is quite capable of going to the 150ma under cranking so its not about the drive output to the actuator. Plus all the senosr can be measured going into the fuel module. Stefan | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 47 Registered: 7-2009 |
Sorry meant to attach a the file.
Second sheet, chart on the left. Stefan | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 48 Registered: 7-2009 |
Richard, Maybe I'm flawed in my thinking. But RPM is revolutions per minute. Hz is per second so to get them to the same base the rpm needs to be divided by 60. Either that or my guage is way out. Stefan | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1945 Registered: 4-2003 |
OK, as I noted, with a single coil it has 4 pulses per revolution or 67Hz at 1,000RPM. If driven by one of the twin coil low tensions, then there are 2 pulses per revolution, or 33Hz at 1,000RPM. That is of course if the tacho is driven by the ignition. It will be obvious on the test bench. With the 100Hz setup I mentioned, for a 4 cylinder motor or an 8 with twin 4 cylinder distributors like ours, the tacho should read 3,000RPM. Looking at it your way will give the same answer: 1500RPM, two pulses per revolution, 3,000 pulses every minute, 50Hz. 3,000RPM = 6,000 pulses/min, 100Hz | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 49 Registered: 7-2009 |
Richard, I mixed things up. Was measuring the crank sensor and combining that with the 2 coil packs. Sorry. This fault is doing my head in. When I measure the frequecy from one coil pack it all makes sense. 50hz is right for the 1500rpm as I see 20ms between pulses. The tacho is derived from one of the coils. Stefan | |||
| Stefan Morley Experienced User Username: myupctoys Post Number: 50 Registered: 7-2009 |
Hi, Went to a car meet tonight. Hotted up japanese stuff. Oportunity to listen. They are all revheads but do get a lot out of their machines. Something one of them said was interesting. Dont trust a Emissions test in a motor registry to give you the full picture, trust it on a dyno. Seems a bit rare but I had a look at my defect paperwork, there is just a box ticked. Not much else. Doesnt pay to ask too many questions if they are ticking boxes. Based on ealier disciussions I think I will take my catalytic converter off tomorrow and see what transpires. Udo my first pressure guage was faulty. Should get new one end of the week so we can compare readings. Stefan | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1951 Registered: 4-2003 |
Stefan, They are surely correct. However, standard-spec fuel-injected motors are not so critical as others. A good mixture on idle certainly does not indicate a good mixture on load in all situations. You may put wildly incorrect SU needles on carburettor cars and tune for a perfect CO output on idle, yet have something really lousy when driving hard. Many Silver Shadows, and especially MkVI and S cars, are so poorly set up that way. With carburettors, the air filter and induction system health is so often very poor, and setting to a good CO reading on idle often corresponds with fouled plugs, burned valves, and rotten behaviour on all but idle. At least with fuel injection, the air's volumetric rate determines the fuel squirted into the system. For example, a clogged or non-standard air filter on an injected motor will not affect the mixture. If the system is set up correctly during manufacture, only the idle mixture need be adjusted during the life of the vehicle unless modified, for example by changing the fuel type and spark timing, the compression ratio or the camshaft profile. By comparison, with carburettors, dirty or non-standard filters can only be corrected on a dyno and with a range of needles to select from to set the thing up on load. That's why I don't give a toss about air filter brands with injection, but do with carburettors. Putting a cheapo or non-standard air filter on a MkVI can only be successful if accompanied by $1,000 of tuning and needle selection on the dynamometer. That’s also the way I had to go with my R-Type when I fitted a high-lift overlap long-duration camshaft and a high-compression cylinder head. With our unmodified injected cars we have it easy. RHT. | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1952 Registered: 4-2003 |
A concrete example of the above. Many people like to fit low-restriction air filters to our cars, especially to English-spec MkVI cars. Watch out. More generally: Low restriction air filters, K&N being classic examples. Carburettor naturally-aspirated cars: a disaster. The motor runs very lean on load and burns up its valves and cracks the plug insulators. Eventually the pistons say goodbye. Dynotuning is required. Injected naturally-aspirated cars. No adverse effects. Increased air rate is rewarded by increased power availability as the injection system matches fuel to air flow. If only the filter type is altered, no Dynotuning should be necessary. This is often referred to as Stage ½ performance tuning. Injected Turbocharged cars: no change as the Turbocharger compensates for everything. No power increase is achieved. Carburettor Turbocharged cars: same as carburetor non-turbos except for the few pressurized-chest carburetor cars like the rare early Bentley Turbos. RHT. | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 51 Registered: 7-2009 |
Richard, Thanks for that, makes a lot of sense. The air fuel mix should always be optimal because the turbocharged/fuel system by it very nature compenstates for changes. Took the converter off, no blocks, looks good. Except the bolts snapped despite onight covered in penetrene. Oh well minor detail nothing an ezy out wont solve. Will wait on my boost/vacuum guage. Cheers Stefan | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 52 Registered: 7-2009 |
Udo, Reason I'm adding a boost/vacuum guage is I want to compare the real state of affairs against the measured voltages from the APTs. They should be one and the same but will let you know. When I get the converter back on!!! Car sounds pretty mean without it on, head turner for all the wrong reasons. No didnt take it out, just moved it back into the garage. Stefan | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1953 Registered: 4-2003 |
The question has always been WHY was a boost gauge never fitted in the first place ? Our T-Series doesn't even have that boring and useless temperature gauge, nor a voltmeter or outside ambient temperature gauge, and doesn't need them. The car looks after all that. Surely a Turbo boost gauge on our Turbocharged cars would be interesting at least ? RHT. | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 53 Registered: 7-2009 |
Richard, Maybe mundane things like the engine operation is beneath consideration. But the outside air temperature well that is a lot more important. I found a link that made me feel a little better. Wont put the link in as parties might get upset but search for "troubled bentley" in google. Your troubles will seem irellavant. Stefan | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 401 Registered: 6-2006 |
R-R couldn't cope with the amount of calls they got about gauge readings etc,which were correct – so they thought it easier to drop as many as they could.... When the first turbo Bentleys came out - there were inundated with customers ringing up or calling in because their "TURBO LIGHT" in the middle of the dashboard wasn't coming on! 'There's something wrong with my turbo!' The outside temperature gauge was crucial for health and safety reasons. Because of the automatic air condition, occupants of the car may have got "Thermal Shock" when they alighted from their cars! | |||
| Udo Hoffmüller Frequent User Username: udo Post Number: 54 Registered: 2-2008 |
Stefan, I will be in Portugal from this Friday with the Bentley. For the next three weeks my access to the internet will be limited. There are many public WIFI places in Portugal, in parcs or bars, but I will not always have the laptop with me. But even then the voltmeter will be fitted to the APT and/or solenoid, just for fun to see what is going on there. To me happened the same as to you: Suddenly the whole thing works correctly for some time! Also for this reason I am surching for an electrical cause. Regards - Udo | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 57 Registered: 7-2009 |
Hi Udo, Enjoy the drive to Portugal. The difference a boost/vacuum guage in the car makes. So much clearer than looking at numbers on a DMM, an old analogue multimeter might have been a bit better. I'm only barely getting 1.5psi boost. The upper value varies a little bit by say +/-.5psi. The APT DMM reading confirms that. What the DMM doesnt show, but the guage does, is when I get to that point, the boost alternatly jumps between say 1.5psi and 0 and that happens about the 2500rpm mark. The jumping seems random. Now I've checked the exhaust system, dump valve both operationally and physically. All the aux bits now work. Only leaves the turbo, wastegate and or the boost controller. The boost controller is definetly getting all the right info and I had that box out and there is nothing physically wrong on the circuits. There is almost no play in the turbine and it spins freely. Not much left other than to look at the wastegate. I checked it as far as the manual suggests in driving pressure down the line and your supposed to hear it click. Which it does. Anyway off with the wastegte to look at that. If it wasnt sealing fully, part of the gasses would bypass the turbine accounting for the low pressure. What is happening to the toggling of the 1.5psi >> 0? Might simply be the wastegate seating and unseating with play and leaking like a sieve. Intermittantly it has worked but incresingly getting to the point I have a normally aspirated car. Will keep you posted. Will take photos if I find anything wrong. BTW fitted my new TPS. Not the easiest job. In case peoples are wondering whats in it here is a pic of the old one dicesected.  The Dump Valve innards  The Air Metering setup, in case people are wondering the brass thing near the wastegate solanoid is my replacement for the platic one way check valve used for the gearbox kickdown. Heat made the plastic one brittle.  Cheers Stefan | |||
| Omar M. Shams Experienced User Username: omar Post Number: 48 Registered: 4-2009 |
Great stuff Stefan. Do you have a picture of the manifold pressure guage set up? Thanks Omar | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 59 Registered: 7-2009 |
Hi Omar, Inside the car is very agricultural at the moment. The guage is "Blu Tac"ed to the column shift temporarily. Not really sure where to fit the guage so it looks the part without changing the look of the dash. The engine vacuum tap is taken off the line going to the vacuum switch. You can see the "T" in the photo just to the right of the Dump Valve solanoid. Stefan | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 60 Registered: 7-2009 |
Omar, As i said very agricultural. But until I figure that how to do a decent unmolested job this will do.  Stefan | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 61 Registered: 7-2009 |
Addition, When cold the guage sits about 16.5inches, after warmed up about 18.5inches. Very Stable. When the Idle speed solanoid cuts in the guage drops (ie air conditioner on) about 1 inch. At 100kms, trailing throttle (no throttle), in second (somewhere around 1500rpm) about 24.5inches. Reading what I can about vacuum guage readings I think the engine is fine. Be interesting to see how this compares with others. BTW the voltage from the boost APT roughly corresponds. Just a lot harder to see a trend on a DMM. Cheers Stefan | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1958 Registered: 4-2003 |
Stefan, What's that speedo that you have there ? The puny 220km/h ones were superseded in March 1987 by the 270km/h ones. | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 62 Registered: 7-2009 |
Richard, This car is a strange one. Assorted interior parts have 87 and 88 written on them along with my cars serial number on them, but the chassis number is comes up as an 89. Most of the circuit boards have reference to being made in 88. Also 89 and a vinyl roof!!! Seems a little bit out of vouge. I thought that idea went out in the late 70's. Other slighly out of the ordinary things is square headlights (like a spirit) metalic paint job and picnic tables. Three years to make a car.... No Idea. Maybe the orgional purchaser was a bit slow in his payments. Stefan | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 63 Registered: 7-2009 |
Richard, Chassis number SCBZS0TA4JCH22888. I think the J refers to 89!! Stefan | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 64 Registered: 7-2009 |
Richard, The other thing (looking at http://rrtechnical.info/ChassisNumbers/sz_vin.pdf) "OT" is defined as a non catalyst pre 88. Yet my car does have a converter. Coupled with "J" for the year 89 and "ZS" Turbo R prior to 89. Got no idea. Stefan | |||
| Eugene Oleinik New User Username: eugenerus Post Number: 7 Registered: 8-2009 |
Stefan, Do you have a build history? This will tell you what happened to your car before it was given to the customer. It will most likely even tell you when and how the customer paid. My car was also made over 3 years, initial order placed in 90 and the car dispatched in 93. I found build history most useful and it will tell things like the key numbers, colours, serial numbers of components used, original features and the package, assembly and driving test results, paint job rectifications, first customer name, order changes (e.g. on my particular example the customer changed their mind and asked the factory to fit the flagpole on the opposite side to what was specified) and any invoices and payments. Eugene | |||
| James Feller Frequent User Username: james_feller Post Number: 72 Registered: 5-2008 |
Hi Stefan, Just answering your question re 'square headlights like the Spirit' late 88 for 89 model years the Turbo aquired its new front air dam and side and rear skirts. I think 89 was the year Crewe changed all Bentley models from the old rectangular 'Spirit' lights to the paired 7' rounds ones. Yes I would agree with Eugene, see if you can get the orginal build history Stef. My Turbo seemed to have been built with lightening speed compared to my Spirit. The build date is June 89 and its Aussie compliance was Oct 89, so 4 months to ship it to Aus. Where as my Spirit is Built Sept 86 and Aussie complied Aug 87. Big difference!!! I'm not sure why you would have 'many parts form different years' on your car. Richard pointed out something I noticed too, strange your speedo doesn't go to 260? yours being an 88 car Stefan. I have wound my Turbo out to 200 and its sensational, although 260 might be pushing it.....!!! What does its build plate say? If you have the hand books when was it first delievered to the first owner? This should be a good starting point. You can track its delivery history and service history through David Vann in the RROC. Provided of course it was serviced at RR&B as there was a requirement that copies of paperwork and service book vouchers went back to RR&B in UK for Achiving. Its worth it Stefan and its interesting reading. I requested the hisoroty on both my cars and little tit bits like the orginal spec sheets and trim requests to England are eveen included... anyway, all 89 and on Bentleys got the paired headlights. You can get them retrofitted but the jet wash feature will be useless or more so than it already is... Cheers J | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 65 Registered: 7-2009 |
Thanks James and Eugene, Yes I will try and track down build details. The car history is known since 2003 but not much before other than it came from Japan with very low kms. It has been well cared for, state of the oil and engine bay is testament to that but as for RR serviceing, not since 2003. Irritating the book isnt with the car. As for the lights they are a part of the cars history and it would be wrong to play with them. The car intermittantly used to go well. Just the fault is no longer intermittant more permanent. Touch wood I'm getting close to the root cause. Cheers Stefan | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 66 Registered: 7-2009 |
James, Eugene, Tried doing a quick search for David Vann with no luck. Assume he is attached to the UK branch. But found no reference to him. Would one have access to this information being a member, seem more pertinant to become a member of a local branch in OZ than UK. Seems to be something on this page http://www.rroc.org/page.asp?SID=1&Page=3 (link "Car Records 1980 to 2002" in left hand column) but password protected. Thanks Stefan | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 67 Registered: 7-2009 |
Hi, Reading the manual and looking at the wastegate doesnt seem to be as simple an operation as it states. Might take a bit longer, the drain return from the turbo gets in the way of simply removing the wastegate. Fortunately the nuts are in good condition. Stefan | |||
| Eugene Oleinik New User Username: eugenerus Post Number: 8 Registered: 8-2009 |
Stefan, RREC UK holds all build records in their archives so it makes sense to order it directly through them (Barbara Westlake, records archivist). More info can be found here: http://www.rrec.org.uk/History/Construction_and_Test_Records.php Note that this is available to non-members of RREC too.  I note your other thread titled Pressure Regulator - the build history will give an answer to similar questions. | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 405 Registered: 6-2006 |
Stefan - The Japan link may answer a few questions and be worth looking into. Speedo's for Japan were probably the reason for the lower top speed calibration. Also things like over-speed ecu's were fitted. I don't know if there is a list of country specific differences anywhere, but as you look through the parts books, you'll see astrix's on many parts - you then need to look at the additional info box. The build sheets may show up these items as well. | |||
| James Feller Frequent User Username: james_feller Post Number: 73 Registered: 5-2008 |
Hi Stef, David Vann, is the achivist for the Aust RR branch I think. I got his details from one of the L&D newsletters some years back. I'll send you his details by private email. Paul has a point, as your car from your accounts looks to be a Japanese spec the complete service history maybe difficult. However the original build sheet should easily be available from the RREC UK as Eugene suggets. Cheers J | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 408 Registered: 6-2006 |
Stefan, not sure if you've read this - or how much is applicable to your vehicle. Might be helpful though?
| |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 68 Registered: 7-2009 |
Thanks Eugene, James and Paul Will contact him. Be interesting even if I cant get the full picture. The pdf is similar is many ways. Can see what Udo is on about in relation to some of the tests he has run. From what I can see most of the stuff is functionally similar. Minus fault codes in mine of course, also they make comments about on road, full load tests that the earlier manual doesnt really make clear. The symptoms for the wastegate describe my circumstances pretty closely. Only difference is mine is toggling randomly, could be attributed to a weak spring. Before I pull off wastegate etc etc. The Garrett T04B Turbo chargers are easy to get parts for. The external wastegate is not so easy. From what I can gather the Wastegates on the Bentleys are also made by Garrett, however from two distributors they suggest Garrett no longer make the external wastegates. Offering alternative modified solutions. Has anyone found or had need to find a source of parts for the wastegates? Cheers Stefan | |||
| Omar M. Shams Frequent User Username: omar Post Number: 52 Registered: 4-2009 |
Paul, Great article.... I am unable to view the images though. Is it my computer or is there something wrong with the document? Thanks Omar | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 411 Registered: 6-2006 |
Omar, neither. The graphics are via the links to other documents. The post is a PDF I made of teh main article. Have you got a copy of Assist? It's tucked away on there. Cheers, Paul. | |||
| Omar M. Shams Frequent User Username: omar Post Number: 53 Registered: 4-2009 |
Thanks for your reply Paul. I am either too old or that PhD was a waste of 4 years of hard work.............. I can't seem to view anything but script on the attachment. I have to say, the stuff that I can read is very good indeed - It is just a shame I can't see the whole document in all its glory. | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 412 Registered: 6-2006 |
Omar. Sorry, I mustn't have explained that properly. The PDF I posted is JUST the script. The original article had the links embedded into it and those links were to the graphics. Do you have a copy of ASSIST 1990 - 2000? Are all your cars pre 1990? Even so, lots of the items are the same or similar. It's a great resource but infuriatingly non-intuitive. Although saying that, it's still much better than many other manufacturers. I stumbled upon the article when looking for something completely different. | |||
| Omar M. Shams Frequent User Username: omar Post Number: 54 Registered: 4-2009 |
Paul, I do not have a copy of ASSIST 1990-2000 or for that matter 2009. In fact I don't know what ASSIST is!! My cars are indeed all 1990 and older. I will go on the net to look up this ASSIST thing now........... Many thanks again. Omar | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 413 Registered: 6-2006 |
IETIS? | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 69 Registered: 7-2009 |
Hi, The pdf gives a lot better indication of how things are intended to function. The things that makes the cars similar is greater than the things that make them different. Specifics certainly change but the background function seems to be very similar. Garrett TO4B Turbos as I said are easy to get parts for. Ordered a rebuild kit just in case I make a mess. You can even get ball bearing retro kits to replace the bushes and 360 degree thrust bushes if one so desires. Apparenlty standard is 270 degrees. The Wastegate is another story. From Garrett they no longer make and support the external wastegates. Also three other of my normal sources have nothing. They might be very reliable and infinitely repairable but this poses a problem. Guess have to take a punt and take it off and see what gives. Touch wood it'll be simple. Stefan | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 70 Registered: 7-2009 |
Omar, I couldnt read the charts either. Its not just you, just so you dont feel bad. I've sent Barbera at RREC.org an email. She is yet to respond but I'm looking forward to anything that turns up. Its quite feasible there is a governing of top speed given the car is japanese, but that doesnt account for my fault. Plus the car used to respond beautifully for my purposes. I spent ten years in another life maintaining helicopters, french, english and american. One thing you get to appreciate is the design methodology in making those aircraft maintainable. Things that are likely to need maintenance have had thought into how that would be carried out. The number of things I've come across with the Bentley, whilst they are beautifully made; the irritating access. Anyone who has tried to replace a steering rack will attest to that. The wastegate is no different. Stupid position for the Turbo return oil drain pipe in relation to the wastegate. Oh well love the beast. Stefan | |||
| Eugene Oleinik New User Username: eugenerus Post Number: 9 Registered: 8-2009 |
Omar, Stefan, Assist, also known as TSD6000 is a collection of technical materials for our cars (90 onwards) that contains workshop manuals, parts manuals etc. They come either as a DVD or as a printed material. DVD is much better though (and costs less too). I do not posess a copy of these but have ordered one recently and believe it will be a very good investment. | |||
| Omar M. Shams Frequent User Username: omar Post Number: 55 Registered: 4-2009 |
Eugene, Thanks for the explanation. I think I should invest in a DVD. Where do you get them from and how much? Thanks Stefan, I have finally got the car back from the steering leak saga. I have RT to thank for helping me out on that matter - Many thanks Richard. I am getting acquainted with the car again. I can safely say that I have an ECU near the front suspension tower making my fuel injection system different to yours. I have also established that the turbine spins under exhaust pressure. I could see the compressor spinning at idle suggesting the turbine/compresor assemly are good. I then ran the engine with the inlet hose disconnected and felt a good flow of air through the air supply hose downstream of the turbo compressor. I did establish that the air filter is embarrasingly dirty. that will be rectified with all haste. My next task is to fit a boost guage to monitor manifold pressure whilst driving. I will keep you posted. Are there any tests you want me to do for you to help you with your woes, or is it not worth pursuing given the differnce between the two injection systems? | |||
| Eugene Oleinik New User Username: eugenerus Post Number: 10 Registered: 8-2009 |
Omar, I sent you a PM with the details. | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 71 Registered: 7-2009 |
Hi Omar, The boost guage should tell a story. I did take my wastegate off and cleaned it. Fault changed slighlty in that is seems to hold the 2psi boost now. Still not the root cause although slight improvement. Ordered a fuel pressure guage with sender unit. Want to see what the fuel pressure does under load. High pressure fuel lines runnig into the car is not my idea of fun, hence the sender. Will post picture of wastegate just so people can see the internals tomorrow. Also tested to ensure the "engine running sensor" wasnt intermittantly turning the fuel pump on and off. That is fine. Dont think anything is wrong with the boost side of things. It is a symptom. I have also been able to get the symptom to occur in neutral in the garage under no boost condition. Not as obvious as when driving. Get your gauge mounted that will help a lot. Will update on the fuel pressure stuff in a couple of days. BTW Discovered from Barbera, my car was German and it was an 88. Things unfold!!! Looking forward to getting the rest of the stuff. Cheers Stefan | |||
| Omar M. Shams Frequent User Username: omar Post Number: 56 Registered: 4-2009 |
Stefan, German????? and RHD? how very strange. No wonder it took so long to make your car. I imagine there are not many cars sent to Germany with RHD, unless of course it was purchased by NATO staff who intended to return the car back to the UK after their tour of duty was completed. This used to happen a lot in the late 80s, but normally with lesser cars than Rolls-Royce or Bentley. | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 72 Registered: 7-2009 |
Omar, Yes I know. I have prodded Barbera to confrim there a couple of other details before she copies the stuff. The square headlights, paint colour and especially the everflex vinyl roof should be unique enough to verify there werent two cars made with the same serial number. The things that support the Japanese connection are mods in line with the Japanese spec (althouth that could have happened when imported to Japan), Japanese writing on the visor, the fact it is RHD. All will be revealed in the fullness of time. I have noticed another symptom (may or may not be connected with the fault at hand). When I get to the rev range in question I have a noise (thought it sounded like a relay) coming from near the fuse panel. I have touched each of the relays and none are clicking. Thats what made me check the voltage driving the fuel pumps from the "engine running sensor". But I did feel something that was consistant with the noise coming from the vent system top right of the fuse panel in the ducting. This occurs stationary in the driveway. Hard to pinpoint the exact source but its certainly being transferred to this ducting. See the picture.  May be coincidental but to happen at that rev range???. Do people know what is in the ducting. I did read somewhere that fuel was fed though a cooler on some models assocaited with the air conditioner but didnt think it was my model. Where would this be situated. To happen at the rev range in question is it coincidence, if there was a fuel cooler in the ducting could substantiate a fuel pressure problem. Like the effect of water hammering when the regulator is no longer able to regulate. When I get the fuel pressure sender that might help. Cheers Stefan | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 73 Registered: 7-2009 |
Hi BTW the air conditioner was off and the fans are off and the car is statioanry with no boost running at 2500rpm. The point is something is happening in or around this ducting enough to transfer the noise and it shouldnt be related to anything AC wise. Maybe another wild goose chase. But seem to remeber someone else talking about a buzzing in a similar area on his forum and also on a German forum. Although they never tracked it down. Stefan | |||
| Omar M. Shams Frequent User Username: omar Post Number: 57 Registered: 4-2009 |
Stefan, the fuel cooler is in the engine compartment on the same side of the engine as the oil filler cap. It is merely a heat exchanger. | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 75 Registered: 7-2009 |
Omar, Thanks. Based on that I dont think I have one. Can see the fuel line and return but doesnt go through anything like a heat exchanger from the manual. Something must be making that noise in the ducting. Maybe air in the coolant line for the heater, similar vicinity. Wild geese and all that. Stefan | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 76 Registered: 7-2009 |
Thinking, While I wait for my fuel pressure sender I'm thinking, what else! What would happen if the crankcase breather unit was not working correctly. These are uniqe in their function for the turbo'ed cars and from what I can see common among years. There is a valve diaphram that changes position based on the boost, if that where a problem and caused it to toggle. Dont know. As promised, the pictures of the Wastegate. Cleaning the gate seating improved retaining the boost marginally but not the root cause.   Stefan | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 77 Registered: 7-2009 |
Hi, Dont know what it means but I pulled apart the crankcase breather unit. Someone had worked on it before and they got the diaphram around the wrong way, possibly not sealing properly. Spring was right side just the sealing seat and cup the wrong way.  Yet to take it for a drive, but another thing put right. Stefan | |||
| Omar M. Shams Frequent User Username: omar Post Number: 58 Registered: 4-2009 |
Stefan, I have attcahed images to show you the fuel cooler on my Turbo RL. I bet you are jealous of the amount of sand and dirt under my bonnet..... you have to work extra hard to get an engine compartment as dirty as this one!!!   (Message edited by david_gore on 20 September 2009) | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 78 Registered: 7-2009 |
Omar, My car doesnt have one of those. Assume the pipes at right angles are the fuel lines feeding into the AC line heat exchanger. As long as the dust stays on the outside of the engine, ie air filters and an oil cap that seals. The bigger killer in Oz is our roads. Big distances and population densities means something has to give. Barbera confirmed my cars details. Definetly German, RHD and 1988. The engine number, vinyl roof and trim colour match. Well travelled car, Germany, Japan and now Australia. History I wasnt aware of. Cant help but wonder if it went to Germany as a RHD that maybe a japanese business man or diplomat bought it, mindful of where he ultimately wanted the car to end up. Hopefully the paperwork will clear things up. Purely conjecture, but there must be a story behind Germany and RHD. Cheers Stefan | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1961 Registered: 4-2003 |
Better check with Udo. However, being EU, Germany has to allow RHD. Yes, England is sorta EU. Germay does tax cars with an earlier emission system out of existence: many thousands of $ yearly even for a catalytic converter system of 5 years before the latest. The motor industy in Germany rules, so all old cars go to Poland. Or to Australia like yours. Because of the Ueberabstimmungsgenehmigung (help Udo: is that just Swiss ?), all cars from the EU Before 1988 and after 1995 are even allowed to be registered in Switzerland. Hence my Turbo R ex-Zuerich, now puffing around Canberra since Friday. That's when AMAG and Emil Frey AG had their cartels broken. Even the Swiss Post use RHD Volksis: easier to empty mailboxes without climbing out of the humble Golf. Stefan, to see if your car really was delivered in Germany, post a picture of your spare tyre carrier. The Germans have a super-safe spec to ensure that the spare cannot drop out and level a castle when you hit 270 on tha Autobahn. Bouncing spares for 10km are not popular in the land of the spicy sausage. RT. | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 81 Registered: 7-2009 |
Richard, Will take a picture tomorrow, but dont think there is anything beyond whats in the manual. Threaded screw and a little hook catch into the centre of the rim. Think I'm on the home straight with the fault or was that faults. Seven so far and only two of them related to age of the car. People working on cars that just dont care about them. Got to 5.5psi and it was rising before I backed off. Still an issue at around 0>>2psi but once its in full flight no issue. Everything seems to be working right now, think the remaining issue is mixture too rich casuing the knock sensor to back things off. What type of slot is the mixture adjustment screw? Cant see down the hole and cant find anything other than an RR special tool number. Thanks Stefan | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1963 Registered: 4-2003 |
Stefan, It's a standard Bosch Allen key thingo, T-handle and shank, like used on any common BMW or the like. An Allen key will do, although the Bosch tool is an Allen key with a wobble end profile, not that it needs it. Once you have removed the tamperproof plug on the chest, it is all a doddle. Crewe has a UR344srat4s4g8TY7-eerqw33 part number decoy, but every Bosch shop has one on every bench. RHT. | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 423 Registered: 6-2006 |
Stefan, Note what Richard mentioned about the tamper proof plug. Some also had a flat head blanking plug. "However - Everything seems to be working right now, think the remaining issue is mixture too rich causing the knock sensor to back things off." I'm not sure that too rich will make the knock sensors operate - too rich is probably better if anything. Also the mixture adjusting screw only adjusts the idle Mixture, doesn't it? Be aware that it only needs a fraction of a turn as well. Are you using a 'good brand' petrol and the highest octane you can obtain? Have you tried an octane booster in the tank? Have you tried with the knock sensors disconnected? | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 82 Registered: 7-2009 |
Richard, Thanks for that. Think I have one of those in my kit. If its what your on about they are called hex ball drivers. Paul, At about 1.5>>2psi (roughly 2500rpm) I have an issue still where it will intermittantly toggle to 0>>0.5psi then back to 1.5>>2psi. I tried it with the wastegate line blocked and it still exists. This occurs when I acellerate up a hill from say 60>> 120. However if I am going along at say 100 (roughly 2500 in second, up hill or on flat) and give it a bootful the boost is happy to climb till I get apprehensive (highest 6.5PSI). The dump valve has been pulled apart and checked, as has the wastegate. I think my mixture is a bit rich, bit too much soot on the tailpipe. Not bad but bit more than other cars I have. Petrol wise 98 all the time. I realise setting the mixture only sets the idle. But am I right in thinking that setting the idle mixture sets a certain pressure for idle (therefore mixture) then this is only added to based on the mechanical metering aspect (other than the EHA compensation). So if you where wrong at idle, and you look at the chart for the boost compensation which is greatest at 2500rpm then being wrong at idle is only going to be worse at 2500. If it where right at idle then the mixture would be right the whole way through as the electronics through the EHA and intrinsic nature of the mechanical fuel injection deal with it. So close i can almost taste it. :-) Cheers Stefan | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 424 Registered: 6-2006 |
Stefan, Checking and adjust the CO certainly will do no harm. tbh I'm not sure if it will affect it across the range or not. But it's a relatively simple thing to adjust and usually a first step to along with a fuel filter. It's surprising how many problems this solves.  Did you take it for a run with the the O2 sensor disconnected and the knock sensors disconnected since you did the wastegate? Is there any difference if you disconnect the battery (*not* switch it off) and then take it for a drive immediately afterwards? Good luck | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 83 Registered: 7-2009 |
Paul, Thanks will give the mixture a go, already changed the fuel filter. Although I have a cat converter the car doesnt have an O2 sensor. What I thought was an O2 sensor is actually only a thermocouple going to a warning lamp, required for the Japanese spec. Assume when your referring to switching off the battery is an attempt to clear any fault code errors. Valid for the Motronic not so for the KE2, has no fault codes that require clearing. Althought when I was playing with things I had turned the battery on and off anyway. No I havent disabled the knock sensors since I did the wastegate. Easy enough to do. Cheers Stefan | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 425 Registered: 6-2006 |
Hi Stefan, I was thinking of the correction parameters on the ecu. Not sure if your year does adjust accordingly. Turning off the battery allows a memory feed to still be supplied on some cars, hence the disconnect the battery. | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 84 Registered: 7-2009 |
Paul, Now you mention it. There is a memory fuse in the boot and I think that bypasses the main switch straight to the battery. I know it supplies the seat memory controller, clock and radio, cant remember a wire associated with it to the ECU. Will disconnect and see where that leads. Cheers Stefan | |||
| Omar M. Shams Frequent User Username: omar Post Number: 63 Registered: 4-2009 |
Stefan, I fitted a boost guage in place of the ambient temperature gauge - and what a revelation that has been regarding manifold pressure!! I have learnt that my car behaves like a nuturally aspirated car till around 2300 rev/min. Then we get boost which seems to be good around 2500 rev/min. and higher. The maximum pressure I have seen under hard acceleration has been 5 psig. I now know that I don't have enough boost pressure especially at the lower end of the rev range where it is needed most. I also know that my turbo does work and can deliver the required pressure if everything did work properly. I will have lots of things to look at, so how about some guidance from your lessons-learnt as to where to start? Thanks | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 93 Registered: 7-2009 |
Hi Omar, Been a bit busy replacing a head gasket on a toyota camry. First time I've done an overhead cam engine. Seems to have gone well, time will tell. Assume your boost has vacuum as well. Useful to know what the manifold vaccuum is doing. When idling cold, idling hot, idling with AC on (bit of load forcing the idle speed solanoid operate) and then on trailing throttle where you are at about 1500 to 2000 rpm (ie down a hill in second). Tells you a lot about the health of an engine. By the look of it your car seems to be at the same stage as mine. From your description my car was intially a lot worse. Least we are at the same stage. I've been through almost all the systems. The two areas I have left are the in tank fuel pump and the turbo itself. I have a fuel pressure sender but trying to find a way of fitting it that wont cause issues is a pain. Thats my plan for the moment, see what the fuel pressure is doing when under load. Already tested statically and thats fine. Flying spares have a kit that does away with the in tank fuel pump. They havnt been able to tell me what that does to fuel delivery though. Irrespective I will be ordering a kit as it has the gasket for the unit. The other area is the turbo itself. While it seems to spin freely I have no idea how freely it should spin. Bought a reduild kit. Easy to get from Ebay in the states and japan. Seems the TO4B is a popular turbo beyond Bentleys. Will let you know about fuel pressures when I can adapt the sender unit. Not so sure how to test weather the tubo spins at the rate its supposed to for a given volume of exhaust. Think if the in tank pump reaveals nothing will just rebuild the turbo. Look at the manifold vaccum under the described conditions. Mine are earlier in this topic. Cheers Stefan | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 94 Registered: 7-2009 |
Eugene, Got my chassis number records from Barbera. Defintely German, RR queried the validity in the order form. But all I have is the Car Yard in Germany that sold/imported it. Dont know the reasons beyond that for RHD. Maybe see if the yard still exists and ask. Thanks for putting me onto Barbera. Stefan | |||
| Eugene Oleinik Experienced User Username: eugenerus Post Number: 16 Registered: 8-2009 |
Stefan, you're welcome. What is the name of the German company? Koenig Auto? In the case of understanding what's wrong with the car, it not so much important for whom this was built, but more important as to what specs it was built. And this should be clearly stated in the build sheets (mine says build to UK spec despite being shipped to Russia). Look closely, the history should reveal the customer name too, unless it's a top secret. The customers name should be in the initial order and possibly in the paper from the German dealer that was mailed back to the archive. | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 96 Registered: 7-2009 |
Eugene, West German company Auto Becker DusselDorf, build is Europe spec. No cutomer name though only the agent, plenty of stuff confirming RHD and questioning which country to build for. Good reading. Stefan | |||
| Omar M. Shams Frequent User Username: omar Post Number: 65 Registered: 4-2009 |
Stefan, My vacuum readings are very similar to those you had reported earlier. I too have a sound engine based on these results (only 62,000 Km from new). Why did you change your TPS (looks like a female-dog of a job to me)? I doubt very much that the turbo needs an overhaul as there is vey little to go wrong there. You are right to look at fuel pressure though!!! For me, I will start by looking at the wastegate and then take it from there. | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 98 Registered: 7-2009 |
Hi Omar, Yeah mine has 88k on it so they should be similar. The idle position for the TPS was fine but I couldnt adjust the get the full load position happening. Switch was dud. Yes it was a pain, involved removing the Idle speed solanoid and a lot of patience trying to get the screws started. The symptom that I fixed cleaning up the wastegate seat stopped the boost toggling (ie held pressure). Must have been a poor seating although the seating looked good, done with a bit of steel wool. You need to diconnect the drain tube from the Turbo to remove the wastegate. Easy enough to do by removing the two bolts either side and pushing it slighly to one side to allow removal of wastegate. The other thing I did was adjust the mixture using a proper vacuum guage (not an in car boost/vacuum guage as they have a restrictor to even out the readings). Works well. When the car is hot, whilst looking at the vacuum guage adjust the mixture screw till you find the lowest vacuum reading then adjust to the rich side of the peak. I saw about 2 inches drop over too rich to too lean range. Less than a quarter of a turn is the most you should need to move it. Too far and the car will stop. BTW 3mm hex driver does both the sealing screw and the adjuster. Improved the carbon on the tail pipe significantly. The symptom I fixed with this, other than the carbon build up was the RPM point I have an issue with has changed to 2600rpm and the power is is a lot smoother. So playing with the fuel seems to be in the right direction. Tend to agree with the turbo. Mine spins freely enough with very little lateral play and no axial play. Got the kit just in case and it was cheap enough. The way I view it is there isnt enough exhaust volume to spin the compressor up high enough. Fuel mix too lean, poor compression, blocks in exhaust, turbo wategate being bypassed, dump valve leaking all could do that. Finding why that is so is the crux. Functionally confirming parts work and disabling aspect of the system and still not have the boost work properly means there is something beyond the boost controller. The boost controller is responding to these problems and complicating the symptoms but removing it from the equation and still have reduced pressure means the issue is elsewhere. The remaining things that I havnt looked at properly is fuel delivery under load. That and the Turbo itself. Have a fuel pressure sender which I want to connect to the lower chamber on the fuel distributor. There is a bolt hole ideal for that. However my sender is to big to directly screw into it so need to come up with a threaded tube to allow it to be connected. Need to figure out the thread and make something. Could just replace the in tank fuel pump but I want to measure to be sure I have a problem and see a positive change when I fix it. Despite the remaing issue, the car feels a lot lot better than when I first started. Stefan | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 99 Registered: 7-2009 |
Omar, Put the fuel pressure sender in. Nothing wrong. Car running get 78PSI from the lower chamber and steady as a rock through the whole rev range. Grrrr was hoping for a clear problem with a reasonably easy solution. Not really sure where to next. Question. Where does your temperature guage sit when warmed up. Just wondering as mine seems a bit low, may just be the way they calibrate the meter. Stefan | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 449 Registered: 6-2006 |
Stefan, did you measure the pressure at the metering head? Coolant temp should be 1/2 way through the white. Transmitters do go out of scale over time. Gauges are usually good though. | |||
| Stefan Morley Frequent User Username: myupctoys Post Number: 100 Registered: 7-2009 |
Paul, Attached to lower chamber where the bolt is.  Is that a good indicator? The main pressure from the regulator is 88psi but difficult to couple into. The only other spot really is from the injectors. My temp guage doesnt have a white band, but normal running is somewhere around 1/3. Reasonably stable. Stefan | |||
| Omar M. Shams Frequent User Username: omar Post Number: 66 Registered: 4-2009 |
Stefan, My temperature guage sits in the midle of the range although on hot days it creeps a little further up the scale. I wonder whether a new set of injectors is what we may be looking at??? If fuel pressure is good, then could fuel flow be the problem? Or are we barking up the wrong tree again? Perhaps it is the old "insufficient air problem again".............. More thinking rquired as you say...... | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 101 Registered: 7-2009 |
Omar, Guess if fuel flow is a problem, testing the injectors and or the top chambers is the last thing in the fuel system. Taking the injectors out the right side doesnt seem too bad but the left looks like a pain. Not conviced about looking at this, the car idles beautifully if injectors where a problem surely it would be rough as guts. Concur with dogs barking. Spark, air, fuel and compression, the rest should just follow. Want to pose a theory. Most people ignore gearboxes till they have a problem. Maybe a change of transmission oil once in a blue moon. Just talking from experience with other cars. Anyway what would happen to the engine gas flows (input output and relationship of different throttle positions) if the torque converter become one to one too soon because things where blocked. The only symptom I have other than lack of power is the knocking sound I mentioned earlier (17Sep). Sounds like a relay but dont think it is, earlier picture shows where the sound was coming from, as best as I can judge whilst driving anyway. That noise happens at the RPM range I have an issue with. My train of thought is if the gearbox was 1:1 too early that would load the engine where it couldnt rev any higher, ie less exhaust gas, less compressed air from the turbo. If the engine is doing a certain RPM, opening the throttle more when the engine it forcebly tied to being one to one what does the do to the volume of gasses flowing through the turbo. Anyone know the effects on an engine if a torque converter became 1:1 too early and what might cause that? Stefan | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 102 Registered: 7-2009 |
Omar, My temp guage also shifts a little on hot days, maybe less than 1/4. Sounds very similar other than yours sitting half way. Paul, Is the bolt indicated in the photo a good spot to measure the fuel pressure? Guys, Still have a gut feel, considering people either go wow over these cars or wonder what the big deal is, makes for a common thread irrespctive of models. Gearbox is certainly common, think they used the GM400 for well over 20 years. If a piston is forced, by being 1:1, to be only able to go at a certain velocity, it will only be able to suck X amount of air in. That combined with the intrinsic nature of the fuel injection would force the correct mix in, this couldnt really increase much because the velocity of the piston cant increse irrespective of how much extra throttle you give. Fuel mix would still be correct as it is about air flow acting on the metering vane. Therefore the exhust gasses arent going to increse much and the turbo can only spin up so far. Does this sound plausible? Cheers Stefan | |||
| Omar M. Shams Frequent User Username: omar Post Number: 67 Registered: 4-2009 |
i like the theory Stefan. However, these gearboxes are bullet proof and have been istalled in so many different cars for decades with no concern. The fuel system however, is delicate compared to the agricultural nature of the gearboxes. That is why I am keen to look at fuel. If the fuel passages developed a coating of 0.001" internally, what would that do to fuel flow? This is my trail of thought regarding injectors........... More time needs to be spent thinking........ Keep up the good dialogue Stefan. Omar | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 103 Registered: 7-2009 |
Omar, Fuel flow, at least in my case seems to be proven not to be an issue at least to the lower chamber. Not sure how to sample one of the injectors under load. Should be about 55PSI. Agree the gearboxes are bullet proof. Doesnt mean they cant fail. The Turbo R's in comparrison to the Rolls Royce have significantly more power, ie more asked of the gearbox. Gearbox is one of the few things I have not touched since I bought the car beyond checking the oil. Just dont know what impact on performance a gearbox beoming 1:1 early has. Paul mentioned somewhere the gearbox should be 1:1 around 2800 rpm, my issue is somewhere around 2500 and at those rpm I'm getting about 3PSI boost. If I got to the extra 300rpm would I see that boost increse to 7PSI. So what holds it back. Early on I was finding clear faults worth rectifying. But for the last couple of weeks nothing is coming to the surface. Aaaargh Stefan | |||
| Omar M. Shams Frequent User Username: omar Post Number: 68 Registered: 4-2009 |
Stefan, I agree in principle with your thoughts - and yes it is a good thread to follow. Having said that........... what a shed load of work to take the gearbox out in the first place, let alone stripping it!!! then to look for something very difficult to identify. Never mind, we will go there if we have to, but let it be an ace up our sleeves for the time being. Consider this: What if that new pump you installed was less than perfect and did not deliver 100% of the intended flow? is that impossible? Now let us assume the fuel pump is a good one. i don't know how many Japanese import cars you have come accross, but here in Dubai, we seem to get them all. Consequently I have had about ten japanese cars all of which (without exception) have had one kind of fuel related issue or another. They seem to have a different type of fuel there that we don't have in Dubai. Their fuel gums everything up, and almost every car I have had from there has needed its injectors cleaning/replacing. I am relaying memories of a Saab 900 turbo, a Saab 9000 turbo, Lancia Thema V6, VW Corrado, VW Golf, Rolls-Royce Silver Spur, Daimler Doublesix.... and a few more that I have forgotten about. In my previous message I had talked about the possibilty of a 0.001" deposit on the internal surfaces of the fuel system. We alll know that the dimensions inside injectors are small enough to make 0.001" a serious problem. what about the fuel distributor? what if the internal surfaces of that have a deposit of 0.001" on them? what would that contribute to? I like your idea of the torque converter locking up prematurely (or simply stuck), but I want some more thinking time focused on easy to remove components first. What do you think?? Have you seen any evidence of brownish deposits on any fuel related parts that you have removed so far? The stuff is alomst like a shellac. Omar | |||
| Omar M. Shams Frequent User Username: omar Post Number: 69 Registered: 4-2009 |
Stefan, I thought I would show you an image of my turbo guage installed and functioning. Even the illumination is spot on......... good match really. The colours on the dial match the fuel guage too.   Hi Omar - the next time you post images, please use the "ENTER" key on your keyboard twice to insert a double space between each image insert command. This avoids the problem of two images appearing side-by-side necessitating repetitive scrolling across the page to read the text. Regards David. (Message edited by david_gore on 05 October 2009) | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 104 Registered: 7-2009 |
Omar, Guage is a good fit, works well, black backgound helps. Fair enough comments. The old fuel pump and the bolt I accessed the lower chamber looked clean enough. Might see if i can remove at least the accessable injectors and see what transpires there. Fuel pump delivery wise. If the fuel pump couldnt keep up with delivery then I would have seen the pressure drop when I got to the 2500rpm. Gearbox wise was just thinking of removing the pan and changing the filter over simply because I should have done it anyway considering I dont know when it was last done. Agree dont fancy taking the whole lot out, least not without some conclusive proof. Stefan | |||
| Omar M. Shams Frequent User Username: omar Post Number: 70 Registered: 4-2009 |
Stefan, I had an assistant watch the turbo guage whilst I floored the car. You really need two people to see the guage properly whilst at full pelt - and be safe. The most boost we got (viewing the guage from the passenger side and considering paralax) was 3 psig. Feeble if you ask me!! I have a new theory for us to ponder. There must be a common issue between our two cars. They are both of a similar age, both are Japanese spec and both have similar mileages. I want us to elimnate the possibility of pressure loss in the ducting downstrean of the compressor wheel. Could air be escaping through rubber hoses that expand under pressure revealing tiny cracks that are not visible at atmospheric pressure? I would like to make dummy blanks and apply static compressed air to see if I can hold a 7psig pressure. I also want to see if air is escaping from other components - not just the hoses. Who knows what we may find? Then again, we could be on yet another wild goose chase. Never mind, we would have chased many geese by the end of this excercise, what is one more eh? I agree with your idea of changing oil in the gearbox. You lose nothing and it is always a good precaution anyway. I have a less than 5% hope of it working towards pinning down a solution to the lost performance on our cars though. Another thing we should be doing is keep thinking!!! we will nail this eventually!! | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 105 Registered: 7-2009 |
Hi Omar, That noise near my ducting, thats what lead me to thinking about the gearbox, fluids air pockets and all that. Need to order a filter before I get around to that. Interesting thinking about holding pressure. Would aerostart or some other stuff around sprayed around joins whilst idling help? I did wonder about seals after I took the top ducting off. Realise things would act differetly under vacuum as opposed to pressure but never know your luck, if the leak was big enough. I was enjoying the process while I was finding clear faults to rectify. We will figure it. BTW my car was origionally German delivered, built to Eurpoean Spec, then shipped to Japan. Found that out via Barbera from http://www.rrec.org.uk/History/Construction_and_Test_Records.php thanks to Eugene. The delivered doco is a great read. Cheers Stefan | |||
| Eugene Oleinik Experienced User Username: eugenerus Post Number: 18 Registered: 8-2009 |
Stefan, since you are changing the filter, I would recommend ordering a full kit - a sump gasket, filter and an o-ring. Specify that you want the kit for the 3-speed gearbox. I didn't and was sent a kit for the later cars with 4 speed boxes. | |||
| Omar M. Shams Frequent User Username: omar Post Number: 71 Registered: 4-2009 |
Stefan, Did you figure out what that noise was in the ducting? With the compressor wheel fully exposed, I could see that there was significant build-up of soot and dust around the vanes. I used an electrical cleaning agent (something we call CRC Lectraclean) to carry out a compressor wash. I am sure you know all about washing compressors in the helicopter industry. You also know the signifcant power gains associated with cleaning small particles of soot and dust from larger multistage compressors. You can therofore extrapolate from that the significance to a smaller compressor that only has a single stage covered with the same size particles that reduce power on much larger units. I am hoping to see an improvemnet on this matter as there was a lot of crap on the compressor disc. I also overhauled my dump valve and found that it had been incorrectly built (gaskets on the wrong side). I am too tired now to refit things tonight, so will try a garage session tomorrow. I can now almost work with no airconditioning in the garage...yippee... | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 106 Registered: 7-2009 |
Eugene, Thanks for the heads up. Flying spares have a kit but will make sure its for the 3 speed. They stuffed up a while back sending me a rear strut for a 92 RR not an 88 Bentley. That cost a bit in shipping from Oz. Cant speak highly enough of them for the most part though. Omar, No I havnt and it bugs me. What I'm going to do is let someone else drive the car and see if I cant pinpoint exactly where its coming from and what its related to. Pretty certain its not a relay but for all intents it certainly sounds like one. Havnt checked my exhaust side of the compressor but your right. When running at over 100k rpm doesnt take much to stuff up efficiencies. Especially a compressor out of balance. My inlet side is pretty clean. Have you pulled off the Turbo? We have had a late spring, jumpers still in order. That and we had a big dust storm last week. East coast copped it bad, us not so bad. Cheers Stefan | |||
| Arthur F. Unregistered guest Posted From: 210.50.228.4 |
Stefan and Omar, Most commercial repairers when faced with power loss issues such as those described would run the car on a dyno with an exhaust gas anylizer attached to check air/fuel ratios at all engine rpm and load conditions. This might have to be your next step.I am watching this post with great interest and your efforts so far has been thorough and worthwhile and i'm sure everyone will be thrilled when you eventually nail the fault! (Message approved by david_gore) | |||
| Omar M. Shams Frequent User Username: omar Post Number: 72 Registered: 4-2009 |
Arthur, Thanks for your interest. For us, we just want to get all those lovely horses that are trapped in a lost enclosure somewhere. It would appear that we are all having fun getting there. The dyno maybe a useful tool down the road if this issue gets us beat. Stefan, Here are two clicking noises that drove me mad on my old Silver Spur (same age as your car and with the same dash layout as yours too). The first one took me a week to find, but shamed me by its simplicity. I had reset the odometer and the internal plastic gear had not fully engaged in the speedometer. Every time it did one revolution, it emitted a clicking noise that amazingly appeared to come from the glove compartment. The second one was a stuck a/c actuator that wanted to keep making its internal limit. If it is either of these, good luck. I have not removed the turbo yet. Where did you get your turbo rebuild kit from and roughly how much did it cost? When inspecting the compressor disc, I felt more play than I would have expected from such a high speed device - so maybe the bearings are shot. I need to establish what sort of free-play is acceptable at the centre of the compressor wheel in due course - perhaps Paul knows. When I looked at the compressor suction hose, it was breached. unfiltered air was able to enter the compressor. Not good!! This will be fixed, but will have no impact on solving our problem. | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 107 Registered: 7-2009 |
Arthur, Agree, will be giving a couple of people a ring to see what that would set me back. I assume it will show a problem. Probably relationship with loss of power and increased or decreased gas mix. Not sure it will tell us where the problem is, just that there is one. Would be a lot happier to get it done once I know I'm onto the root cause and we need to get things set right. Will talk to them though. Omar, Ended up with two kits from two sources just in case. Pretty cheap. 50>>80AUD. http://myworld.ebay.com.au/kando_dynamic/ and http://myworld.ebay.com.au/japan_precision/ although the latter doesnt seem to have any at the moment. Whilst I am yet to use the kits the look well made. The bearings are actually bushes, did see a site that allowed one to upgrade the bushes to bearings FWIW. Might have even been Garrett, cant remeber. Greater likely hood of being an AC servo given where I can hear the noise. Thing is, the noise only beomes apparent when I hit my RPM of concern. Not there at any other time, including playing with AC. Good to know about the servos though. Will hit my car with some Aerostart when I get some. Whilst my hoses look in good condition not so sure about the rubber Oring on the throttle body. Also want to come up with a way of measuring the injector fuel pressure under load. Need to come up with a threaded T piece first. Cheers Stefan | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 108 Registered: 7-2009 |
Omar, Not sure what measuring the injectors will tell me as the fuel distibutor would probably have to vary the pressure a bit to increase flow against the mechanical component of the injectors. But if it drops then we are onto something. Found a site related to Mercs a couple of days ago (seems they used a similar system) that made mention of the rubber gaskets in the fuel distributor wherent happy with some additives in fuel. Didnt make specific mention of what additives, other than the origionals suffered with later fuels. We will see what the pressure monitoring will tell. Not convinced as if this gasket was stuffed all the pressure regulation to the injectors would be problematic and would show up at other RPMs. The gaskets are quite complex with integrated rubber diaphrams forming the pressure regulation to the injectors integrating the gasket function as well. Stefan | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 109 Registered: 7-2009 |
Omar, Been thinking about your theory of loss of air under pressure and if that relates to my findings. Wind things back a bit. After I cleaned my wastegate I mentioned I got to beyond 5psi, that was with the wastegate disabled, with it enabled still get what your getting about 2>>3PSI at the manifold. Irrespective of the boost controller doing whatever its doing which is aberrantly turning power off to the wastegate solanoid thereby allowing pressure to open the wastegate. The wastegate must be opening otherwise I should still get to 5PSI with it connected. Therefore somewhere in the vicinity of >7psi must be in this line. Losses seen elsewhere before it gets to the manifold. Be patient, trying to cohereantly convey my thoughts. The wastegate pressure pipe gets tapped directly from the outlet of the turbo, the boost pressure we are monitoring is at the manifold. For whatever reason the boost controller is doing its thing however, if the Turbo is actually boosting to the >7psi as seen at the tap then this would feed that pressure to the wastegate and open it. The fact that there are losses due to leaking gasses actaully monitored at the manifold could explain things. Also thinking the Aerostart would only be really effective after the throttle in the manifold. Idling, the vacuum before the throttle would almost be non existant given there is no real restriction. Easy enough to test for. Monitor the pressure in the wastegate pressure line. Will follow that train of thought. Stefan | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 110 Registered: 7-2009 |
Omar, The other thing that adds up...... My 5.5Psi (wastegate disabled) plus say the 7.8psi normally the wategate will try to regulate boost pressure to, (if it where connected) gives 13.3Psi. This is close to the pressure the dump valve will open at to protect the engine. Therefore if the leaking theory follows I have about 8PSI leakage. Biggest likelyhood of this sort of leak if the theory fits is the throttle body gasket or a gaping hole. Be nice. Will measure the wastegate pressure control line. Cheers Stefan | |||
| David Gore Moderator Username: david_gore Post Number: 913 Registered: 4-2003 |
For what it is worth - the Mercedes reference may be to the effects of ethanol blended fuel on the synthetic seals etc used in fuel systems prior to the introduction of ethanol blended fuel. It is my understanding R-R/B fuel systems from 1990 are compatible with E10 however earlier systems will require the replacement of seals/diaphragms etc with ethanol-compatible parts. I don't think this is the problem but is one that could minimise future problems arising from the mandated use of ethanol blended fuel. | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 111 Registered: 7-2009 |
David, Thanks, sounds fair. Wonder how quickly the ethanol denatures the old seals. Probably pot luck. Peoples Found something worth a photo. Took the Cast Elbow off. Look at the arrows. This is only apparent on the front edge of the throttle body. Note I havnt cleaned this. Looks like a pretty good indicator of a leak. The Oring that forms this seal is a little flattened. Have asked for quote on a new one. In the mean time I've cleaned the old one and rotated it and put a little grease on it to help it seat.  Will test after lunch although might not be conclusive till I get new Orings. Cheers Stefan | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 112 Registered: 7-2009 |
Omar, After cleaning and reseating the Oring on the throttle body, with the wastegate disabled easily got to 6.5PSI then somthing happened and it dropped to 3PSI. The throttle body shows some leakage of the grease (stuff I smeared on the Oring) on the front of the throttle body. This is definitely one source of an issue. Also the other thing the tapping sound from the ducting wasnt there as I was climbing to 6.5PSI but returned when it dropped to 3PSI. Possible makeing and breaking the ORing seal (who knows). Will get new Orings. There is still the separate issue related to the wastegate path. Will fix Orings first and work on the wastegate path later. Stefan | |||
| Omar M. Shams Frequent User Username: omar Post Number: 74 Registered: 4-2009 |
Stefan, You appear to have made good progress. My throttle-body is also exposed now, but it was not easy removing the inlet pipe connected to it. perhaps mine had a good seal at that location. Put it this way, it WILL have a good seal when it goes back. I will start by checking the o ring condition. I am trying to get the intercooler out to see if that has a leak at the moment. Also, I want to insepct the rubber pipes in and out of the intercooler. I will update you on my findings. keep the quest going. Here is a question...... Are we reading manifold pressure correctly? could it be that our 3 psig downstream of the throttle body is not the controlling pressure upstream of it with some losses in between? Omar | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 113 Registered: 7-2009 |
Omar, I dont have an intercooler. Makes life a little easier than yourself. Assume your talking the dump return pipe. There is a big lip on it thats a bit tough to get off. I think we are reading the manifold pressure correctly. Both the APT vacuum lines are connected to the same section of the manifold. The controlling signal for the wastegate is tapped from the turbo banjo connection and fed via the solanoid down to the wastegate. Pressure wise the pressure at the Turbo banjo connection is probably higher than at the manifold given the restriction on the Turbo Outlet. Waiting for response to my Oring quote. Also going to see if i can get a new Wastegate solanoid as my origional was sticking, even though I since cleaned it up. Stefan | |||
| Omar M. Shams Frequent User Username: omar Post Number: 75 Registered: 4-2009 |
Stefan, I meant the inlet casting that has the O ring in it (the one you are replacing now). That was tight on the throttle-body in my case. I have since looked hard at the O ring and yes it is flat. Needs to be replaced. Just got that damn intercooler off. What an awful task that is!!! I have filled it with water to see if holds overnight, but after the weekend I will make proper blanks and for it and pressure test it to 9psig. I think it will be fine although I will take the opportunity to clean the internal surfaces whilst I am at it. | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 114 Registered: 7-2009 |
Omar, Okay, mine came off easy. Thinking about it part of the problem might be my cast elbow doesnt sit down quite far enough at the front of the throttle body, maybe 2mm, looks fine at the back. Determined by the length of the two hex mounts. When I get the new Orings might look into shortening the front one slightly. Be nice to be able to statically test the whole boost system in situ. More easliy said than done. Good luck with your tests. Was thinking about the Aerostart technique. Idling, if one restricted the inlet pipe from the air filter considerably then the whole system before the throttle would be under a slight vaccuum and leaks would draw in air. All about degrees, boost though forces seals and leaks into another dimension. Ruminations Stefan | |||
| Laurie Fox Frequent User Username: laurie_fox Post Number: 65 Registered: 6-2004 |
Stefan and Omar I am only a MK VI man but have been following this thread with much interest. I have made several pressure measurements on my cooling system in order to find out what was going on. The flow rates in different places made the readings of static pressure difficult to interpret. I would have liked to get total head readings and/or some actual flow figures but did not figure a way to do it without turning myself into a fairly full blown engine developer which I was too old to do. But the results I got were most useful in relation to the way I run B420EY and have been reported in this forum. I commend your activity and the way in which you have kept all of us in the picture. It takes me back to my early days of test flying with experimental wing sections, multiple manometers and wool tufts to see where the flow changed from laminar to turbulent and so on. Regards Laurie | |||
| Omar M. Shams Frequent User Username: omar Post Number: 76 Registered: 4-2009 |
Laurie, Many thanks for your encouragement. I am all too familiar with chasing my own tail....(done that once or twice so far...). I think we have made some headway today. Read on: Stefan, I have some news!! The pressure test (all be it confined to 3 components) revealed leaks I would never have suspected. I took the intercooler off and pressure tested the cooler with both hoses attached. I used food tins (unopened - offcourse) as bungs and introduced air through the drain point on the cooler and held a opressure of 9 psi. Within seconds that pressure went down to 7, then 5 then 3 and held there. Upon retest, I got a bubbly soap solution and invetsigated. The flexible hose that connects the discharge of the intercooler to the intake casting is a metre long 4" diameter hose that looks good to the naked eye (both images below show the overall condition of this hose). Under pressure, the pipe swells and tiny perforations open up. Not one or two..... many many perforations. There were bubbles coming out of my ears. At a lower pressure, the bubbles did not stop completely, but reduced drastically. The other astonishing thing was the connection to the inlet of the cooler. This rubber hose is a substantial preformed shape that should have a lifetime of at least 50 years. it is the one that connects the compressor discharge to the intercooler. The hose was fine, but where it is secured to the cooler (using a jubillee clip), that clip needed to be super super tight in order for the bubles to stop coming out of that joint. It all suggests that a "low pressure" of 7 psig is not as low as one would think. Sealing that low a pressure is not that simple. This now leads me to suspect every joint and every hose in the system. They must all be treated with suspicion. I intend to test partial systems one at a time. You mentioned that you replaced an in-line check valve with a brass aftermarket one. Good decision. Do you have any details? I am sure the two I have must be hopeless I am now looking to see if I can find an aftermarket hose as I feel I would need a mortgage to buy a new one. The banks are not being kind these days......   | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 115 Registered: 7-2009 |
Laurie, Bits of string on AC, last time I saw that was a perfect bit of test equipment, called a telltale and used as a slip indicator. So simple and works like a charm. Not quite the same as testing the laminar air flow of a wing. Omar, That intercooler is quite a proposition, surprises me it isnt bigger given the volume of air the system would have to contend with. Guess any cooling of the compressed air is in the right direction. The check valve is 300PSI reverse and 1PSI forward. Will ring up later to find out who made it, I bought it from adealide pneumatic. Works fine. Only have one check valve on my car and thats to stop boost being forced into the gearbox kickdown. Definetly know its stuffed when the car refuses to change into third. Will update details later today. Great to hear youve found some significant leaks. Faults that can be indentified are good. The potential of leaks in my car is a lot less. I think most of mine are from the throttle body to cast elbow interface. 10 pounds from Uk. Might have a little bit of a leak from the hose on the dump valve return line but thats after the event so not so fussed about that. The only other leak point I have is the interface betweent the dump valve and cast elbow. Not sure about this but the ORing is flattened as well. On the surface 7PSI doesnt seem like much. Deceiving. Mind you at 7PSI with the 6.75L engine that is quite a volume of air when you think about it. Cheers Stefan | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 116 Registered: 7-2009 |
Omar, The check valve is made by clippard, about $13 ea. Warning this file is a bit big, Page 155 of http://www.clippard.com/downloads/general/PDF_Documents/NEW%202008%20Catalog/Catalog%20by%20Section/107-177%20Control%20Valves.pdf If you cant get them locally contact me privately and we will sort something out. Whilst I wait for my Oring, toying around with why my wastegate might be complicating the issue. Either the boost controller is deciding something is wrong or a symptom I saw earlier is the cause. When I forced compressed air in the wastegate solanoid valve, it operated by iteslf. I dont know the exact circumstances (powered or unpowered) but will recheck. But if the internal spring was weak, and I know it was seized prior to my cleaning it, that maybe its bypassing air when it shouldnt. When I get the Oring will confirm the circumstances. Stefan | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 117 Registered: 7-2009 |
Omar, This might be a bit easier. Think this is the one I got. The origional was 0.5psi cracking pressure the new ones are 1psi but at least for the gearbox kickdown line it works fine.  Bought screw in barbs for each end as well. The only irritation is they are a bit long. Meant the existing piping had to be modified to fit the clippard valves. But they will outlive the life of the car. Cheers Stefan | |||
| Omar M. Shams Frequent User Username: omar Post Number: 77 Registered: 4-2009 |
Stefan, Thanks for the check valve details. I am intrigued by your comment:When I forced compressed air in the wastegate solanoid valve, it operated by iteslf. I dont know the exact circumstances (powered or unpowered) but will recheck. I am waiting for the next installment on this matter as I have not gone to this item yet. I think you are very brave to have taken that wastegate off the exhaust when you dismatled it several weeks a go. What an awful job!! I spent so long trying to remove it that I gave up, put everything back together and sent the car to the garage. I figured my time was more expensive than that of the mechanic's - so let him die a thousand deaths removing it. I will overhaul it when he hands it over to me. We are trying to source an intake hose in parallel. All the best Omar | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 118 Registered: 7-2009 |
Omar, Air pressure alone forced the solanoid to open, (ie no power) just cant remember which hose connection I put the air into. Presumably it only really matters if that happened with the line coming from the banjo connection as this is the source of the pressure. Bought all the bits I should need, including a solanoid. Irrespective of having a possible issue with it; it is probabaly only a matter of time before it seizes again. Should get the stuff in a couple of weeks. You and my missus might be right, shades of madness :-) Oh well only myself to blame. Run my own business and in between jobs at the moment so my determination/perspiration is cheap enough while it lasts. Cheers Stefan | |||
| Omar M. Shams Frequent User Username: omar Post Number: 84 Registered: 4-2009 |
Stefan, The hunt goes on for me. I have now taken the turbo off (with the help of my kind mechanic/garage) and the images speak for themselves. My wastegate valve was not seating well nor did it activate properly. The valve seat had a casting defect from day one in the form of a pin-hole. Nothing I can do about that. I have found a very good substitute intake hose to replace the perforated one.  Also, my problems have just started. I found that the turbo boost solenoid was passing. I ordered a new one but they seem to be unavailable the world over - so I took mine apart in the hope that I can repair it. I am starting to feel a little scared now!! However, I will continue to soldier on and will rebuild it over the next 2 days.  I have attached a few more images for general interest.    | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 120 Registered: 7-2009 |
Hi Omar, You have been busy. Photo doesnt reveal the pinhole but if its a pin hole then it will be passing very little exhaust. Seating incorrectly will be a lot greater issue, also the pinhole burning a larger surrounding hole. Both of these would be obvious when you look at the two mating surfaces. Although looks like you've cleaned it up. I bought a new solanoid via Flying spares and should be delivered either today or tomorrow. Along with assorted Orings and gearbox filter. Did you try flying spares, dont think they had them on hand and had to order one in (where they got it from I dont know). Solanoid was 160 odd pounds but at least it solves a problem. Stefan | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 121 Registered: 7-2009 |
Omar, BTW the online flying spares price list only covers part of what they can get hold of. Mainly the common stuff, so its worth contacting them directly. Duncan especally is very tolerant and helpful. I have mentioned to him there are a number of people with similar symptoms on the forum. Just so you dont think they are being rude, they dont tend to offer technical advice but otherwise they are very helpful. When I cleaned my solanoid, all I did was spray degreaser through the holes. It freed it up, it was origionally seized allowing air to permanenlty open the wastegate (assuming the pressure was great enough); didnt pull it apart. After I cleaned the solanoid, I tested the it on the bench, the circumstances I mentioned earlier are; When you put power on the solanoid it is supposed to stop air coming from the banjo connection to the wastegate. Mine stops air at low pressure but when I crank the pressure up to about 4>>5psi (from my workshop compressor) the solanoid suddenly starts toggling, ie it would intermittantly direct air to open the wastegate. That is with power on it. Should just stay closed until power is removed. Not sure exactly whats happening internally but hopefully the new one will solve that little dilema. Stefan | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 122 Registered: 7-2009 |
Omar, FWIW, RR part number for Wastegate Solanoid is UE70999, seem to be the same between years. Got all the bit this morning, should keep me busy for a day or so. Stefan | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 489 Registered: 6-2006 |
Stefan - Stumbled upon this. Don't know if it's even applicable but I thought of you! Dump valve solenoid link loom Applicable to All Bentley Turbo R motor cars from vehicle identification number (VIN). *SCBZR04A0KCH24519* to *SCBZR04A8KCH27507* including *SCBZR03B6KCX27531* *SCBZR04A0KCH27534* Introduction A link loom part number UD 72401 has been introduced to rectify a customer complaint of hesitation on 1989 model year Bentley Turbo R motor cars. Description A problem can exist with the 1989 model year turbo motronic engine management system, where a momentary hesitation can be felt under light load conditions, predominately whilst using the cruise control. The reason for this is, as the dump valve solenoid operates, it can induce an electrical spike, which in turn causes the eprom, housed within the motronic electronic control unit (ECU) to re-set, thus causing the engine to lose power intermittently. A link loom part number UD 72401 has been produced, consisting of a diode wired across the terminals from the dump valve solenoid. This acts as a blocker, eliminating any chance of an electrical spike effecting the motronic electronic control unit (ECU). The link loom plugs into the dump valve solenoid connection, which can be found towards the rear of 'A' bank and should be fitted upon complaint Regards, Paul. | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 150 Registered: 7-2009 |
Paul, Thanks for that. My car has the earlier KE2 Jetronic. However inductive kick from solanoids is just as likely. If memory serves me right there are three solanoids around the engine. Possibly a fourth in the EHA. The boost ECU supplies the wastegate solanoid, the idle speed solanoid I think comes from the fuel module, and the dump valve comes from the vacuum switch. Not sure if they are directly hooked to the ignition ECU, but even indirectly via power lines.... EHA comes from the fuel module. Three of the solanoids are driven single ended style (can hook a reverse biased diode up to stop bemf), the EHA is push pull style (ie reverse polarity). **** Means dont hook a diode on the EHA **** Just making comment in case people read this. The fuel module is made from discrete components, probably not really susceptible to spikes. The Ignition ECU has a processor in it so could be feasibly susceptible to spikes. Certainly worth looking at and easy enough to test for. Should be getting the remainder of my parts next week. Hopefully...... Cheers Stefan | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 154 Registered: 7-2009 |
Paul, Put diodes on the all three of the solanoids and nothing changed. Still worth a try and quite feasible. Spent the weekend doing a few things. Put a new Throttle body Oring in. New Wategate solanoid, rebuilt the dump valve with a new diaphram and Oring. Rebuilt the crankcaes ventilation unit, new thermostat. Only thing left to do for the physical parts of the boost system is rebuild the Turbo but thats not really the issue. Cut to the chase, still have the problem. However I've got a theory which I will be testing out over the next couple of days. The car is working a lot better but still not right. Hopefully :-) It will give people a laugh when I take a photo of what I've done. Couple of days, work pending. Cheers Stefan | |||
| Omar M. Shams Frequent User Username: omar Post Number: 88 Registered: 4-2009 |
Stefan, The excitement is killing me. can you not give us a few clues? I have just collected the car from the garage following a few more minor leak remedial works. The inlet hose that was leaking has been wrapped to see what effect that has had, but we are still at only 3 to 4 psig boost. I swear I can hear the air hising from the system - but where is it? I have a plan to get someone to drive the car with me as a passenger with the bonnet removed to see if I can see the leaks. We have a great liquid that is commonly used in the oil and gas industry called "snoop". It can be squirted though a tube remotely and forms large visible bubbles at the slightest pressure. I am a bit too busy right now for this activity so I will wait till I have a bit more toy-time on my hands before I try this one. Right now, my wheels spin hard if I do a floored u turn so there is little urgency to find the extra 2 psig for me. i have a hydraulic issue with my Wraith that I need to focus on now. All the best. Omar | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 155 Registered: 7-2009 |
Hi Omar, I said the car is running well. Took it well over 200, and could have done it all day. Just have to remain below 1PSI with the throttle. Ie slowish acelleration. Once there, no issue. In second, quite happy to go to 3800rpm, as long as boost is kept below 1PSI. From standing start its happy enough to spin the wheels. But as soon as there is boost of any moment, it releives the pressure. I've taken the boost controller, APT, wastegate solanoid out. Setting up a largish sealed plastic container and hooking the solanoid, and apt to it. Then putt compressed air in the container. Idea being is the system should try to reglate the pressure in the conatiner. Have a signal generator hooked up to simiulte RPM, althought dont think thats the problem area. Given I've tested the controller in the car and none of the signals seems to be having a negative effect I want to see what happens when I control the signal inputs. Everythign else is fixed, and by defeating different things have been able to prove to myself, the car isnt leaking air. Fuel and igntion wise things are running fine. As i said Novel. Hopefully somehting will come out of it. Stefan | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 156 Registered: 7-2009 |
Omar, I rebuilt the dump valve because when the valve lifted off the dump return pipe, it lifted unevenly. It now lifts evenly and holds just under 7PSI before it opens. It has always sealed and functionally operated but think the uneven opening caused the pressure relief operation to open the valve prematurlely and inconsistantly. Not the root cause but every little bit helps. Stefan   | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 157 Registered: 7-2009 |
Peoples, Something that might help prove where I'm going. Can someone measure the voltage on the center pin of the top APT plug(one related to the boost system) with the plug removed. Ie measure the open circuit voltage on the connector center pin. Should be over 5V with the plug removed. How much over in comparrison to the second APT might be the clue. The second is 8V, this comes from the Ignition system and there is an 8V reg on that board. My boost system has 6.something (varies about 0.3V) internally pulled up in the boost controller. My theory is there is nothing physically wrong with the car, more the boost controller has a problem internally where by one of the inputs internally is representing false data. All the external tests certainly show this as the direction. The concept of the boost controller is the wastegate solanoid valve is opened intermittantly in response to pressure measured from the APT in order to regulate the manifold pressure. What that ultimate pressure can be for any given rpm is determined for by the speed signal. The pressure is dropped to min if a number of error conditions are met. Knock, over speed rpm, brake or cruise control or over pressure. Otherwise the unit should try and regulate the pressure by bypassing exhaust gasses around the turbo by intermiattantly opening the wastegate via air pressure. If everythign is right and the air pressure it there, the system should hold things in equilibrium. In the case of overpressure, when it is exceeded too greatly (ie a fault or wastegate permantly shut) the dump valve will be forced open against the internal spring releiving pressure unitl the pressure drops allowing the spring to return and let boost pressure build up again. My symptoms can be any one of the error conditins but I've defeated each those inputs and tested for them. None of them seems to have an impact. So my feeling is something internally is misrepresenting one of those signal inputs. Any voltage measurments!! This voltage isnt in the earlier manual. Stefan | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 158 Registered: 7-2009 |
Peoples, Fixed. Wow..... What I didnt expect was the boost doesnt gradually ramp up like other cars I've owned. It seems to be mapped in steps. But the up shot is the system is regulating boost pressure perfectly. Seems to be in three stages. 2PSI initially and that changes to 4.5PSI above 2600, an area I never really got to before except by defeating the wastegate, even then I had other mitigating faults. Then a third stage when I'm at about 3000rpm where it jumps to 6.5PSI. Earlier tests with my now correctly seated dump valve tells me it releases at 7.5PSI. The regulation is rock steady if you give it enough. Works like a charm. I still have an issue but not related to boost although it has an impact on how the boost system works. Something in my car is very intermittantly chewing a lot of power (can see the headlights dim slighltly every now and then) and that upsets the supply to the boost controller. Defeated the issue temporarily by disconnecting the 60A LHS main engine power loom. (near the spring pillar, just in front of the HSMO containers). Finally the boost system works as it should. :-) Very happy. Now to solve the intermittant power problem. Think it might be the in tank fuel pump. There was a mod kit Rolls Royce relaeased at some stage related to the in tank pump. 50W 2 ohm resister in series with the pump. Assume it was to protect the system when the motor was in a stall condition. Easy fix as Bentley have a mod kit that does away with the in tank pump. Thanks for your input peoples. Once I fix the electrical issue remaining I'm going on a long long drive. Been looking forward to it. Cheers Stefan | |||
| Omar M. Shams Frequent User Username: omar Post Number: 91 Registered: 4-2009 |
Stefan, are you saying that your boost system worked all the time? or did you do anything in particular to see the higher boost pressures? thanks | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 159 Registered: 7-2009 |
Omar, No, the system wasnt working. The faults that prevented it working are, the Oring on the cast elbow, the dump valve not seating squarely, the Wastegate solanoid being opened by air pressure. Dump valve not being seated right meant the pressure release occured to early, even if the system had been working. Secondly the Oring was only partially sealing and at a certain undetermined pressures leaking air. Thirdly the wastegate solnoid not funcitoning correctly meant when it was supposed to be electrically closed it would intermittantly get pushed open by the air pressure. Once I put these things in, the system was still only partially working. The rest of the problem is coming from the electrical issue I have elsewhere. Once that was temporarily worked around the boost controller itself was happy to function fully. Closed loop systems, pain.... Esp one with no diagnostics. Cheers Stefan | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 160 Registered: 7-2009 |
Omar, Should point out there was multiple faults with the boost system. When i first got the car, the boost was intermittant. In hindsight this was the first signs the bits that I replaced where failing. In the process of investigating the problem I found the previous owner had disconnected the 60A connecter I speak of. I found one of the pins to the alternator wasnt making contact (3 pin in a four pin plug on the alternator). I re-connected this 60A connector at the same time. Once I did these two things the issue I had with the lights dimmining occasionally, dissapeared. Figured I'd fixed that issue. Apparently not. However at the same time the boost system became even more intermittant. In hindsight it didnt matter what I did to the boost system, the other electrical problem I have elsewhere was interfering with the boost. Point is the boost was failing anyway irrespective of the electrical issue. Electrical issue was making the problem worse. I was simply revisting some of the things I had done, one being the 60A connector and the boost worked fully. Connected it intermittantly works, but better than when I bought the car. Hopefully that makes sense. Stefan | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 161 Registered: 7-2009 |
Omar, Something worth looking at that isnt very apparent is the dump valve. Mine was sealing and operating correctly at a reasonably close look with the Vacuum switch. What I found was that if you suck on the pipe leading to the dump valve unit it should lift evenly. Mine lifted one side first then the rest. New diaphram fixed it. Lifts evenly now. That manifests itself with the symptom, when the wastegate is disabled (ie pipe removed from wastegate) of only being able to get to 4PSI or there abouts, varies a bit. Fixing the diaphram it gets close enough to 7.5PSI. Thats of course assuming there are no other leaks. It was sealing but presumably boost pressure was finding it easy to lift one side first. Worth looking at. Stefan | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 162 Registered: 7-2009 |
Udo, Havnt heard from you in a while. But thought I'd make comment on the wastegate solanoid openeing at certain rev ranges that we both had issues with. Now I have my system working I know its supposed to open at roughly the rev range your talking about. However this is a closed loop system and the only reason its open is to regulate the boost pressure. Certain rev ranges will change what pressure is supposed to be regulated to. If your knock sensors/brake/cruise signals are fine and you get the revs up to 3000, even in the garage, you should find the wastegate solanoid get powered on again. Watch the gearbox kickdown, ie remove the fuse. Stefan | |||
| Omar M. Shams Frequent User Username: omar Post Number: 92 Registered: 4-2009 |
Stefan, I take your point on board regarding the dump valve. I will buy a new giaphragm and rebuild it a second time to ensure it lifts evenly. As a matter of interest, my cruise control has a problem which may be related to the whole issue. whenever it is engaged, the car regulates speed like a learner driver. one minute the throttle is all the way down, next it is off and it cycles like that every few seconds. In other words it cannot function properly. Is there a link here I wonder? what about your APT/ was that ok in the end? | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 494 Registered: 6-2006 |
Hi Omar, Just a comment on the speed control. That sounds like it is probably the ECU that has a fault. Have you got one to substitute it with from another car? That's the easiest way to test probably. | |||
| Omar M. Shams Frequent User Username: omar Post Number: 93 Registered: 4-2009 |
Paul, Thanks for that note. I do have access to a few to choose from off my friend's cars. Where is the ECU located and is it just a plug it and play thing? Thanks Omar | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 495 Registered: 6-2006 |
Drivers side knee roll down, It;s got a single plug about 8 or 10 pin. Silver 10cm x 2 cm x 15 cm. an ear each side with a mounting screw in each. It looks like you need to take tons off to get to it, but with the right screwdrivers it will come out alone. Plug it in and go | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 163 Registered: 7-2009 |
Omar, Have no idea, other than the cruise control has a line that goes to the boost controller to disable boost when in cruise mode. My cruise seems to work. My APT must be fine or it wouldnt regulate. The center pins of both APT's have a different open circuit voltage (boost is 6.8V and the other one is 8V when unplugged), must be resistively pulled up in their respective controlers. As soon as you plug it in it drops to something sensible. Considering earlier cars only used one I thought they might be similar. Apparently not. The excitation for one (when plugged in) is 5.4V and the excitation for the other is 5V. Excitation difference probably accounts for the .21V difference between my two sensors at atmosphere. One is 2.41V the boost one 2.18V. Manual suggests 2.2V >> 2.8V, considering I'm at 600meters it probably within spec. I did try, swapping the sensor pulgs around, and at one stage coupling both systems together in case I was just swapping the problem from one system to another. Naturally after I had measured that there wasnt going to be any disasters on my hands electrically. Can you just unplug the cruise control module and see if the car functions properly. Thats if you cant borry, beg or steal a module :-) When cruise is on that line is high, to turn the boost off. Same as the brake line. Stefan | |||
| Stefan Morley Prolific User Username: myupctoys Post Number: 164 Registered: 7-2009 |
Omar, BTW when I tried coupling the two sensors together I only hooked the grounds and signal lines in paralell. Not the excitation. Only one excitation was driving the sensor. Both would casue a problem. Cheers Stefan |
Bentley Fuel ECU