| Author | Message | ||
     Omar M. Shams Prolific User Username: omar Post Number: 1934 Registered: 04-2009 |
what is a spark sensor? where does it live and what does it do? | ||
| Darryl Watson Experienced User Username: inox Post Number: 121 Registered: 04-2015 |
Hi Omar, In the manual it is called by several names. E.g. Timing sensor, Spark Sensor. The part number is UE72296. It lives at the front of the engine near the timing pointer. It sends a pulse to the Engine ECU to control the timing of the ignition spark (s). That is my understanding. If I’m wrong someone will tell me. Regards, Darryl | ||
| michael vass Frequent User Username: mikebentleyturbo2 Post Number: 627 Registered: 07-2015 |
Hi Darryl and Omar there are two sensors on on the crank pulley one on the flywheel OK Mike | ||
| Udo Hoffmüller Experienced User Username: udo Post Number: 105 Registered: 02-2008 |
The correct names of the sensors are - CPS crankshaft position sensor - ESS engine speed sensor, later called CKP crankshaft (engine speed) position sensor CPS and ESS are the ones on Darryl's car. They are the same except for the length of the connecting cable. Later the CPS is moved from the front to the rear end of the engine, it is still the same sensor, but now called CMP camshaft position sensor, a resistance sensor. Only with Zytec-cars this sensor is another type of sensor: a Hall sensor. The name changed from CSP to CMP because of the reference pin rotating witht the crankshaft, while the refence pin with CMP (at the rear of the engine) is rotating with the camshaft. With Zytec-cars and Hall sensor there is no reference pin. The Hall sensor uses a single toothed disk mounted to the camshaft. A little bit confusing. Regards - Udo | ||
| Omar M. Shams Prolific User Username: omar Post Number: 1935 Registered: 04-2009 |
This is the perfect opportunity for you knowledgeable guys to help me resolve a 5 year issue that I have lived with rather than fix. Only reason I have not fixed it is because I dont know how to fix it. My 1996 Azure does not idle well. Sometimes its perfect and other times the revs go up and down. When the revs dip below a certain number it triggers the check engine light. I have to reset the light every time it comes on. Recently it has been coming on almost every time I drive the car. The fault code that comes up is P300 multiple random misfire. The plugs and coils are all good as are the injectors. I have swapped out the idle air control solenoid from two other cars that did not have the problem and nothing changed. Could it be one of the speed sensors? If so which one? | ||
| Udo Hoffmüller Experienced User Username: udo Post Number: 106 Registered: 02-2008 |
Dear Omar, the fact that check-engine lights up has nothing to do with bad idling. Check-engine always lights up when the engine speed gets too low, check-engine always comes on below 350 rpm. The reason for this doesn't matter. The PCMB analyses the crankshaft signal and compares the received signal with PCMB store data. The emission test failure thresholds are analysed over 1000 revolutions increments. The programmers have introduced the error code P300 for wrong ignition, e.g. too few ignition processes per unit of time - which means nothing else than too low engine speed. This error message can have many causes, it is actually not very helpful. Actually, I would say: Your mistake could be the one Darryl has already remedied: The air meter potentiometer is faulty, the conductor is worn out at the point of idle, the current can no longer be conducted, the ECM receives no data for brief moments so the idle becomes restless. But: Zytec vehicles as your's do not have an air meter potentiometer. Instead, they have a throttle valve potentiometer that tells the PCMB the position of the throttle valve. The error is the same: a worn track leads to incorrect values that do not match the other values. One of the other important values is the vacuum in the manifold - while Bosch vehicles use an air flow based system with an air meter other than the pressure based Zytec vehicles. This MAP value and the value of the throttle valve potentiometer must match. The PCMB has programmed a table for the manifold absolut pressure (MAP). The sensor is located under the right front wing, where you see inside the engine compartement a rubber house entering the wing (close to the box with the PCMB). So for me first two things to check are MAP sensor and throttle position potentiometer. I hope your car is not confirming to USA or Canadian specification. The CMP (camshaft sensor) has nothing to do with your problem. It is only to tell the PCMB when to start firing, in other words when A1 cylinder is in TDC position. Without this information the engine will not start. If the running engine looses this information nothing happens as far as the engine is not stopped - the PCMB calculates the right moment for firing from the CKP (in Darryl's car ESS). To avoid any wrong or stupid advice, it would be helpful to know the chassis number of your car. My ContiR is MY96, too, but I never had the kind of problem you are reporting. So the advice is somewhat theoretical. I hope, this is of some help. Regards - Udo | ||
| Omar M. Shams Prolific User Username: omar Post Number: 1936 Registered: 04-2009 |
My Dear Udo, At this stage I would like my friend Vladimir to arrange a really hot chick to fly over to your house and give you a big fat kiss. I understand this is not an impossible task. Vlad - can this be achieved? Udo I think you have nailed it!!! The area you took me to has a connector that has 4 terminals that goes into nothing. I imagine there should be a MAP sensor there. Do you have a picture of what it looks like and where it should be screwed into? Oh and yes my car is USA Spec | ||
| Udo Hoffmüller Experienced User Username: udo Post Number: 107 Registered: 02-2008 |
Dear Omar, the sensor is mounted under the right front wing. There are two sensors, one for the turbo, one for the PCMB. They are only accessible from outside the engine compartement. But the plug for both of the sensors is close to the box that contains the PCMB. The plug is easy to identfy because the cables enter the front wing - the only ones in this region. The USA spec cars have an acceleration sensor fitted to the left spring pot/dome inside the engine compartment. This sensor may cause problems - but I forgot the way it is involved, I have to search for more info. My ContiR is british and does not have this sensor. Sorry, I cannot take photos. The ContiR is in Germany while I am in Tenerife during wintertime, here we have the TurboRL and the Shadow. Maybe it looks just like on the Turbo, but I am not sure about that because our Turbo is MY91 with Bosch KE-Motronic. I'll try to find out more about this damn acceleration sensor. Regards - Udo | ||
| Udo Hoffmüller Experienced User Username: udo Post Number: 108 Registered: 02-2008 |
Just to add to the previous post: The purpose of the acceleration sensor is to detect extreme road roughness which may cause resonances of the engine and/or the body and so lead to erroneous detection of misfire. In this case misfire detection should be suspended by the PCMB. If the sensor is faulty you may find your error code P300. The sensor is only sensitive in vertical direction. It must be mounted correctly to not be activated in other direction than vertical. So this is what this (stupid?) sensor may lead to. I have no idea what happens if it is simply disconnected. May be this is impossible because the PCMB must be programmed accordingly. You should take in mind that this sensor in your car may be the culprit of strange misfire error code while the reason for strange engine behaviour is completely different. Herewith we have completely left the original topic. Wouldn't it be better to separate Omar's question and the following answers? Regards - Udo | ||
| richard george yeaman Prolific User Username: richyrich Post Number: 1136 Registered: 04-2012 |
Udo I find all the information above very interesting and as there is very little information on these late cars it would be helpful if they could be moved, my Turbo R vin 60128. Richard. | ||
| Omar M. Shams Prolific User Username: omar Post Number: 1937 Registered: 04-2009 |
Dear Udo, Many thanks for the information. It is truly invaluable. I will not be able to get under the wing until the weekend. I will report back when I do so. So... I need to see three items under the wing. A thing called a pcmb, a turbo sensor and an acceleration sensor. Are these at the front of the wing or at the back?. Will all 3 of these be under the wing? My car also has an intercooler fan under the wing (close to the front of the car) I agree that this excursion needs its own thread and i would request the Moderator to kindly start a new thread with the last 5 posts taken there. The title can be "P300 Random Multiple Misfire" Will do later today when I have some free time - we are doing our best right now to keep the medical profession gainfully employed!!!! | ||
| Udo Hoffmüller Experienced User Username: udo Post Number: 109 Registered: 02-2008 |
Omar, no - you must read more carfully  Under the right front wing you will find the sensors for the turboECU (which is under the left front wing) and the MAP sensor (manifold absolut pressure) which is the important thing to let the ECM (engine control module) know the load condition of the engine - Bosch is using a mass air flow sensor, a completely different way to get information about the load condition of the engine. The MAP sensor under the left front wing is just where the cables enter the wing close to the engineECU. The body acceleration sensor (this is the correct name, abbreviated BA) is mounted on top left of the suspension spring retaining cover - this is the description of the location taken from the workshop manual. Please forget for the moment the PCMB - I was wrong and a little confused about all thouse abbreviations. PCMB is what RR calls the TurboECU which is mounted under the left front wing. Sorry about that. The best of all: You do not need to crawl under the wing. The cables from the sensors lead to a plug close to where they enter the engine compartment (or where they enter the wing, just as you like to look at the cables). There you have to measure with you ammeter if the sensors do work correctly. Look at the first pic - 101 is the MAP sensor, 102 is the according plug where to measure. Just for your orientation: 1 is the engineECU, 79 and in the neighbourhood are the relays for engineECU, fuel pumps pp  Look at the second pic - 131 is the BA sensor  Regards - Udo | ||
| Omar M. Shams Prolific User Username: omar Post Number: 1938 Registered: 04-2009 |
This is excellent Udo!!! I will take a look in the next few days and report back. Do you know what constitutes a working or damaged MAP sensor? the same question applies to the Body Acceleration sensor. Thanks again. Omar | ||
| Omar M. Shams Prolific User Username: omar Post Number: 1941 Registered: 04-2009 |
Dear Udo, I have the body acceleration sensor in place and it looks like a sealed box that will either work or not work. I will leave this item alone for now. The MAP sensor has a vacuum hose that goes from the depths of the V in the engine into a grommet that then disappears behind the wing. The sensor itself must be under the wing. I will need to remove the splash guard below the wing to see the sensor and then report further. For reference the Body Acceleration sensor is a Bosch part 273 101 021. thanks Omar | ||
| Omar M. Shams Prolific User Username: omar Post Number: 1951 Registered: 04-2009 |
I have not yet looked at the MAP sensor but I came across this on the net.......  On my car, the UE 73180 (air pressure transducer) is electrically connected but the vacuum line is not connected. My UT11563 (T piece) is also missing. where the T should be, the two hoses are connected together. I think my first activity would be to reinstate this T and line. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 3018 Registered: 06-2009 |
Omar, I'm coming in for a "drive by" posting based on general experience not specific to RR/Bentley. You are correct that your first course of action should be to restore any vacuum lines to their appropriate configuration and to check that you do not have leaks elsewhere. If you end up replacing vacuum lines, and are not a stickler for exact OEM appearance, silicone line made for this purpose is much more durable (not that the original isn't pretty darned durable to begin with). The number of issues that can arise from vacuum being out of whack are myriad. And you know that no matter what the marque, the engineers were expecting that what they put there is what would remain intact. Brian | ||
| Omar M. Shams Prolific User Username: omar Post Number: 1953 Registered: 04-2009 |
Sound advice Brian | ||
| michael vass Frequent User Username: mikebentleyturbo2 Post Number: 632 Registered: 07-2015 |
Hi guys I've only ever seen this uneven tickover / almost cutting out/hunting problems on cars with cats and air pump, I think the lambda sensors set up a feedback osculation. Just my opinion OK Mike | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 3019 Registered: 06-2009 |
There's *kissing* involved?!! How shocking! [Sorry, I just couldn't resist. It's the first time I've seen osculation substituted for oscillation and it struck my funny bone.] Brian | ||
| David Gore Moderator Username: david_gore Post Number: 3629 Registered: 04-2003 |
Nothing like a good malapropism to start the day..... Thanks Michael for a great start to my day and Brian for adding the finishing touch! | ||
| michael vass Frequent User Username: mikebentleyturbo2 Post Number: 633 Registered: 07-2015 |
Don't blame me it's your spill chucker lol | ||
| Omar M. Shams Prolific User Username: omar Post Number: 1955 Registered: 04-2009 |
Dear Udo, you have solved my problem. I am most grateful to you for that. The missing vacuum line and T was the culprit. My idle is now excellent!! A very big thank you. Omar | ||
| Omar M. Shams Grand Master Username: omar Post Number: 2109 Registered: 04-2009 |
The screenshot above in this thread shows the MAP sensor UE73180 and another MAP sensor UT10648. These look like common Ford Escort parts from the same era as our cars. The Cosworth Ford series of turbocharged cars had the same components. The difference in price between the Ford parts and Introcar/Flying Spares is approximately 800%. The part off my car actually has a Ford part number displayed as V93AB-9F479-AA. Does anyone know which Ford part is used in the turbocharged Bentleys? | ||
| Darryl Watson Experienced User Username: inox Post Number: 149 Registered: 04-2015 |
Reading all of this I am glad I have a “simple” Motronic normally aspirated engine. | ||
| michael vass Frequent User Username: mikebentleyturbo2 Post Number: 699 Registered: 07-2015 |
Hi Darryl I agree,how much more power is achieved by all this? Mike | ||
| Darryl Watson Experienced User Username: inox Post Number: 151 Registered: 04-2015 |
I think in the real world with traffic and road conditions one would gain very little from having the more powerful car(s). Journey times in the UK would be about the same and our “S” more than capable of dealing with modern traffic. | ||
| Omar M. Shams Grand Master Username: omar Post Number: 2122 Registered: 04-2009 |
Just to wrap up this thread..... Udo was my guide on this journey and he was spot on. I ended up replacing the Manifold Absolute Pressure (MAP) sensor which if you scroll up you will see as part number UE73180. Since replacing this part my check engine light no longer comes on. My P300 fault was cured when I replaced UE73180. A huge thanks to Udo for all his help. |
