| Author | Message | ||
     Stefan Morley Grand Master Username: myupctoys Post Number: 381 Registered: 7-2009 |
Hi all, Been a very long time but finally reunited with my car. 4200 km round trip with a trailer, combined weight of close to 6 tons and it's finally with me again. Total respect for the Land Cruiser that did the job. Anyway on topic. Been getting back into the car and it's getting there. Couple of little gremlins I'm working through but none major. New rear tyres (Avons cough, for those that buy them will know what I mean) about to replace all the accumulators. None of that's an issue. People probably remember Bentley power annoyance topic a few years back, or rather got bored with my persistence. Well it is progressing. Fitted a new fuel pressure regulator and that has helped a lot. The old regulator pressure varied too much depending on fuel flow from cold through warm up phase to running temperature. Not much maybe 3>>5 psi but that a mile with the CIS system. So at least now I can set AFR to where they are supposed to be and they stay set. The question I have, and probably only pertinent to people who have studied AFR's on the K, KE or KE2 Jetronic but what can one expect AFR map wise. Clarify the question, I can set the mixture to 14.1 which approximates to the 0.8% >> 1% CO in the manual when at temperature but under "no load" the AFR's drop quite linearly as the RPM's increase and stay at that AFR if you hold those RPM's say nominally 11.9 at 2500 rpm. Have to dig up my logged charts to be specific about the relationship. Would this be what one would expect from the KE2 (with no O2 feedback). Logically to me they should fall in response to the throttle change then climb back up to some nominal point but below the 14.1. Say nominally 13.5 or so, not stay at the linear response position that I'm seeing. I know there is no electronic feedback to make this change but the manifold pressure would change in response to the throttle change which would affect the air flow metering vane. Keep in mind when at operating temperature the EHA only has a base current setting (5.9ma) unless boost or significant load as measured by the APT sensor. So there is no extra enrichment from this direction other than the base setting. Reason I see this as a problem is if I do get to boost conditions or significant load the extra enrichment from the EHA would almost certainly be way too much giving me the symptoms of loss of boost. Effectively almost flooding the engine with fuel. No I haven't taken the car on the road yet after changing the fuel regulator as I haven't been game till I get the accumulators sorted so haven't been able to test under load or boost except in the driveway. I'll follow up with a good map over the next couple of days to outline what I see as a problem. Have a gut feel what the problem might be, if this map is wrong, but don't want to pre empt valuable opinions to make sure I'm in the right direction. Anyway thoughts welcome. Cheers Stefan | ||
| Omar M. Shams Grand Master Username: omar Post Number: 757 Registered: 4-2009 |
Dear Stefan, Welcome back mate. It has literally been years!! I will not be able to help you as I have put my Turbo RL away over a year ago. I am playing with other very nice Bentleys and my old faithful Wraith II these days. Richard Treacy is your man I am sure. Keep us posted with your progress. Omar | ||
| Stefan Morley Grand Master Username: myupctoys Post Number: 382 Registered: 7-2009 |
Hi Omar, Thanks, it's good to be back on the case, and good to hear your still enjoying your cars. Think I sort of answered my own question with help from Richard and others at the time, did a bit of a search and came up with my previous query. "Air Fuel Ratio Setup with EHA" topic. Noticed I did have a logged run that made sense albeit with the fuel pump restriction depleting the accumulator thanks to an undersized washer on the banjo connection, subsequently sorted out. My current logs are way too rich but otherwise make sense. Still to get my logger working properly but think the issue is related to my fuel distributor rebuild and how far the control plunger nut was screwed in, but want to confirm before pulling it apart. Been trying to compensate for the problem by richening the EHA to bring the distributor pneumatic/hydraulic pressures in balance. Which works to a degree at the expense of way too rich across the rev range. Problem I had/have is, before playing with the EHA, under very light throttle the car was too lean until the revs got to a somewhere above 1200rpm. Load or no load. Making the car richer has helped so I can take off without a problem but the AFR's mechanical mappings are too low at the higher revs. This was compounded with poor pressure regulation from the old fuel regulator making it impossible to adjust with any sort of repeatability. That being removed from the equation with a new fuel pressure regulator leaves the distributor/eha left in the equation. There is still a residual clue in that even though I can drive the car the AFR's rise slightly maybe 0.3 before dropping as the revs rise. All I've done is make it a lot richer to compensate, not fixed the problem. Should have taken note of the depth setting of the nut on the distributor but all I have to go on was a photo before I dismantled it. Hardly a good measure to go by. Aside this depth setting think the rebuild worked fine as the car idles and starts fine minus this issue. Noticed apparently Bosch preset these to 0.6mm (based on a Merc article) so maybe that's a start. Stefan | ||
| Stefan Morley Grand Master Username: myupctoys Post Number: 383 Registered: 7-2009 |
Peoples Thinking a bit more, might be that the nut is screwed in too far, pulling the plunger clear of the roller in the air box. Could account for why even though I've made it way rich I still have slight AFR rise before the air vane acts on the plunger. Just not sure why that clearance wouldn't be adjusted out with the mixture screw!!! These things are beautifully simple in concept but the inter related mechanics, hydraulic and pneumatics are not simple. I'll have to get those logs happening. Stefan | ||
| michael vass Grand Master Username: mikebentleyturbo2 Post Number: 554 Registered: 7-2015 |
Hi Stefan Just found this old post, are you all 100% now and going like a rocket? what was the root cause of all you fuelling problems? Cheers Mike | ||
| Stefan Morley Frequent User Username: myupctoys Post Number: 400 Registered: 07-2009 |
Hi Mike and others who helped along the way, Sorry, very late response... years, even. Yes, I found my underlying performance issue. All that Bentley Power Annoyance topic and other topics I started around a similar vein all pointed to the same thing once I figured it out. The previous owner ran the car on E85. E85 is 85% ethanol, 15% ULP. Three biggest clues, #1 Once I fixed a number of peripheral issues, were the fact that I couldn't get the AFR curves set right, and the fact setting the AFR at idle was so critical. Ridiculously so. I know the CIS injection systems are about 1/2 a turn of the mixture screw to be too rich and too lean, but this was a lot fussier than that. #2 Then the fact that under boost at any level just above atmosphere, the car was basically being flooded with fuel. AFR's showed that (once I had fixed the fuel accumulator washer banjo bolt flow restriction). #3 The additional thing that now makes sense was when I took the car for a test drive when I bought the car, it worked like a treat. But over successive weeks the problems started creeping in. Common thread, I was diluting the E85 in the tank with 98..... Stoic point for 98 is 14.7 and E85 9.76. Big big difference. AKA running the 98 when the fuel distributor was setup to deal with 9.76 flow needs, meant I was almost at the cutoff point with the fuel distributor plunger position. Then under boost the EHA was likewise setup to deal with flow needs of E85. Stick 98 in it and the car was basically being flooded. Homework after figuring this out, all that needs to be done to convert a CIS to E85 is to adjust the Allen key adjusters under the fuel distributor to open up the flow; then tailor the EHA adjuster for boost operation then set the AFR's for idle. The EHA can be adjusted to bring the AFR curves into line iteratively. Whilst one won't get the full power benefits from running E85 given the timing isn't adjusted for, the car is perfectly happy to run. E85 runs cooler, has a higher octane rating of approx 107 meaning with no changes to timing the chance of detonation drastically reduces (assuming you have the right amount of fuel delivery) and gives you more power, albeit with approx 30% more fuel being used. If timing and fuel flow is dealt with one can get to 17% improvement, naturally with only fuel flow done be something less than this. There is only one petrol retailer that carries E85 in Brissy but on the plus side the fuel price is a lot more stable than diesel and 98. What has surprised me is given the assorted fuel bits and bobs I replaced, there appeared to be no degredation/corrosion of the assorted bits. Worst case, the previous owner would have run the car on E85 for between 2003 and 2008. That is the biggest fear with E85, its ability to absorb moisture, corroding things and breaking rubber down. None apparent. I did learn a lot more than I cared to learn. But alls well that ends well, and the old girl can certainly shift along. Couple of gremlins, like I need to regas the AC, already fitted a left-hand control arm, rear brake pads replaced. And the brake pressure switch topic peoples might have seen recently. My biggest lesson in all this, assume nothing, and don't give your car to a mechanic that doesn't give a toss about your car. While some things I fixed had been fair wear and tear, there were six things that were unforgivable. I can only hope it was done by a backyard mechanic because if it was a proper mechanic they should be shot. #1 Crushed SS washer extricated from A4 cylinder. Originally thought it was a lifter till I stuck a camera in the pot. Fortunately the pot walls and valves look ok. #2 Missing large Oring from the compressor side of the turbo. #3 Brake pressure switches assembled incorrectly. #4 Bolt missing from the Alternator mount, meaning the crankcase was sucking in un-metered air. #5 Tie downs bent on the jack points. That was done on my watch by a well known suspension place in Oz. Won't mention names. #6 Incorrect washer installed in the banjo connection to the fuel pump restricting flow. I've left it the way it is, other than balancing the fuel delivery for the injection lines after the fuel distributor rebuild. That and I add a stabiliser for E85 to the tank just to reduce the corrosion possibility. If it wasn't for the fact I have an O2 logger (rpm/manifold/O2) I would change back to 98. But I've had no problems since I figured this out. Cheers Stefan | ||
| Stefan Morley Frequent User Username: myupctoys Post Number: 401 Registered: 07-2009 |
Hi All, Meant to add a couple of comments but ran out of time to re-edit. That stainless washer stuck in the cylinder was a stunning revelation. Ever since I bought the car, I would get a ticking sound when the car started till it warmed up. Classic lifter symptom. To find that bent washer in there stunned me, one that it was there in the first place, two it has been there since I bought the car, and three no damage had happened an all the time I drove it. Blows my mind, very lucky.... One additional comment about E85.When I finally figured the E85 issue out, setting up the AFR's for idle was dead simple as was sorting out the AFR curves. So easy and simple that it was child's play. Setup experience was very different to all the grief of trying to setup the system assuming 98 when in fact flows were E85 related. Seems to me one could throw logs of timber in the fuel tank and these cars would still run. Cheers Stefan | ||
| Jeff Martin Frequent User Username: jeff_r_1 Post Number: 567 Registered: 07-2018 |
I didn't read the whole post, but was the washer in #1 piston, maybe someone was trying to find TDC and forgot to remove it ? | ||
| Stefan Morley Frequent User Username: myupctoys Post Number: 402 Registered: 07-2009 |
Hi Jeff, Yep, fair call :-) There was stunned relief when I found it. Been so easy to chip a valve, bend a valve stem, bugger up a pushrod, score the bore..... Compression still good. Not a thing, yet it had been there since I bought the car in 2008 till about 2016 ish when I found it. Despite the grief over the years, she has "never" failed to start. Total respect. Most of the grief was hack mechanics and not knowing the car had been running on E85. There was a steering rack rebuild, and a rear hydraulic strut that was maybe premature FWT; but beyond that, nothing. Maybe one could bemoan the AVON Turbo Speed tyre costs. But they do stick to the road well. Cheers Stefan | ||
| Stefan Morley Frequent User Username: myupctoys Post Number: 403 Registered: 07-2009 |
Hi Jeff, No, it was cylinder A4, IE Looking from the front of the car left hand side rear most pot, or driver's side for a RHD car. Found the source of the noise with a mechanics stethoscope. Not terribly easy even with the stethoscope, given how sound travels in a solid. But certainly narrowed it down to the offending pot. One day I might do a write-up of the meandering paths and things learnt along the way. I do love the old girl, will never be a pocket rocket, but she can certainly hold her own on the right sort of road. Cheers Stefan | ||
| michael vass Frequent User Username: mikebentleyturbo2 Post Number: 794 Registered: 07-2015 |
Hi Stefan Love to see this washer! Could it be from a 10mm plug seal, if someone tried to fit the wrong size plug? Cheers Mike Currently waiting for the rain to stop so I can refit my petrol retun T peice, what a pig to get to. | ||
| Cliff Biggs Experienced User Username: cliffy Post Number: 121 Registered: 09-2021 |
That was an interesting trail to completion Probably the best trouble shooting process I have ever heard of in my 60 years as an aircraft mechanic and car mechanic. Nice job! |
