Title: Engine stalling Post by: José V. Gavilá on July 19, 2007, 11:49:53 am Hello!
Well, my Espace seems to have still a problem :( I thought it was solved with the temperature sensor replacement done by Renault garage, but not, definitely not. What happens is that, when cold, engine starts perfectly. But then, when it starts to get warm (when temperature gauge shows one segment; just about 1 minute from cold start now in Summer), it stalls (or, if you are driving, you abruptly notice engine stops and restarts; you can even see the RED square lighted for a short time). Then, when temperature gauge is at 2 segments, it uses to do it again. And then it works perfectly... I know some of you have had similar problems before... please, could you let me know what other sensors you think could be the culprits?. Based on my experience with other cars, I think there should be a coolant temperature sensor, an air temperature sensor and a pressure sensor. But, remember, it seems to fail only when passing from cold to hot... Please, any help will be welcomed!. Yesterday it stalled while driving in an slow curve, just 1 minute from my home, and I lost all power assistance and was about to crash the car :o . Once it stalled when passing over a train railway... it is scary! Thanks for your help! Regards, JOSE PS: is there any Service Manual for the 3.0 V6 24V engine? Title: Re: Engine stalling Post by: roy4matra on July 19, 2007, 02:47:44 pm Well, my Espace seems to have still a problem :( I thought it was solved with the temperature sensor replacement done by Renault garage, but not, definitely not. What happens is that, when cold, engine starts perfectly. But then, when it starts to get warm (when temperature gauge shows one segment; just about 1 minute from cold start now in Summer), it stalls (or, if you are driving, you abruptly notice engine stops and restarts; you can even see the RED square lighted for a short time). Then, when temperature gauge is at 2 segments, it uses to do it again. And then it works perfectly... Hello José, I'm sorry to say but you appear to have one of those intermittent problems that we in the trade hate. They are extremely difficult to track down, because they don't stay faulty long enough. Often they happen for such a short time that even the electronic system doesn't record an error. Or the cause is something that cannot be recorded e.g. a unit without feedback. To eleborate and clarify this, if you had a throttle stepper motor for instance, when the injection computer signals it to operate, if it has no feedback circuit, the injection computer will have no way of knowing if it has obeyed its signal to the correct amount. If it has a feedback system, then the computer will know just how much it has responded and if it needs to adjust that response up or down. Hopefully that makes it a bit clearer. No-one, including the manufacturers can correctly diagnose the cause of a fault when it is not there. And if anyone else tells you they can, they are lying or don't know what they are talking about. So the only thing that can be done is to experience the problem, have test equipment connected during the time it happens hopefully to pick up the transient error when it happens. If someone has experienced exactly the same fault, and has then found the cure, then they can use that experience to try the same solution and see if it works on the next vehicle. If it does great, and it short cuts the diagnosis too. However, not all faults are caused by exactly the same things, so sometimes this doesn't work. Now I have not seen or heard of exactly the problem that you describe, and I have found no reference to that problem within my documents. I don't have access to the Renault on-line system now (as I no longer work for them) but there may be something that someone else has come across recorded there. Without that possible information, and without having experienced the problem, I can only suggest possible causes. Quote ... Based on my experience with other cars, I think there should be a coolant temperature sensor, an air temperature sensor and a pressure sensor... Yes, the coolant sensor you have had changed. The air temperature sensor is combined within the airflow meter, so to replace it you have to replace the airflow meter; and the air pressure sensor is usually a small unit mounted to the inlet manifold. However, if you had a faulty air pressure sensor, it will not cause the stalling you describe. If the airflow sensor temperature sensing was faulty, I doubt that would cause the stalling you describe either, and it would also not correct itself once it got up to normal temperature. No, the most likely area for a fault of this type, sudden unrecorded stalling and re-starting immediately can be interfence, the TDC sensor, bad wiring connection, or the injection computer itself. We have had many interference problems on Renault vehicles, caused simply by incorrect spark plugs. In my experience Renaults can be very fussy when it comes to spark plugs, and if someone has fitted even what are normally considered good plugs like say NGK or Bosch, these can often create problems that disappear immediately the correct Renault plugs are put in. So we often got cars in with faults where the car had recently been serviced and non-approved plugs fitted, and then the problems started. Once we changed the plugs back to Renault approved plugs, the problems stopped. So the first question is: have you Renault approved spark plugs? Has anything been changed just before the problem started? Was any work done, just before the problem started? These are the first things to examine. I have seen a similar problem on the V6 which was caused by a faulty TDC sensor, but they are a pig to get at and check or change unfortunately. Quote PS: is there any Service Manual for the 3.0 V6 24V engine? Renault workshops no longer use paper manuals, and the on-line system is part of the Dialogys computer system. Each section is a separate file, 0 - General, 1 - Engine, 2 - Transmission, 3 - Chassis, etc. and there are different ones that apply to particular vehicles, like the Espace, but they also don't always have all the engine options for instance since, other engines often become available after they were written. So you have constant updates over and above the original base files. Your engine is the L7X which is often pared with the LM0 auto gearbox, and there is a supplement for just that combination. It was not part of the original file. However, there may be some parts of the original file that will still apply. So if you really wanted to get all the information on your vehicle, you would need all the relevent parts of the Dialogys system - not easy when I don't think Renault will sell it outside their franchises. Was there something specific you wanted José? And in answer to your question about coolant level, it should always be checked cold preferably after an overnight stop so it really is cold. Roy Title: Re: Engine stalling Post by: José V. Gavilá on July 19, 2007, 10:44:56 pm Hello Roy,
Thanks a lot for your interesting answer!. Well, I should say that I have done some electronics work on my 2.0 TCT Citröen XM and that I have a very well equipped lab at home :D so I am not scared about sensors and such ;D I'm sorry to say but you appear to have one of those intermittent problems that we in the trade hate. They are extremely difficult to track down, because they don't stay faulty long enough. Often they happen for such a short time that even the electronic system doesn't record an error. Or the cause is not something that cannot be recorded e.g. a unit without feedback. Yes, I understand this perfectly and know that what my Espace has is a difficult to find problem :(. But we have some clues:
Quote No-one, including the manufacturers can correctly diagnose the cause of a fault when it is not there. And if anyone else tells you they can, they are lying or don't know what they are talking about. So the only thing that can be done is to experience the problem, have test equipment connected during the time it happens hopefully to pick up the transient error when it happens. If someone has experienced exactly the same fault, and has then found the cure, then they can use that experience to try the same solution and see if it works on the next vehicle. If it does great, and it short cuts the diagnosis too. However, not all faults are caused by exactly the same things, so sometimes this doesn't work. Yes, I was thinking in hooking up some test equipment to the ECU... but I would need some technical info, so I asked for the Service Manual; I want to find all the engine ECU info, to learn which inputs it uses to determine ignition and injection timings. Quote Yes, the coolant sensor you have had changed. The air temperature sensor is combined within the airflow meter, so to replace it you have to replace the airflow meter; and the air pressure sensor is usually a small unit mounted to the inlet manifold. However, if you had a faulty air pressure sensor, it will not cause the stalling you describe. If the airflow sensor temperature sensing was faulty, I doubt that would cause the stalling you describe either, and it would also not correct itself once it got up to normal temperature. No, the most likely area for a fault of this type, sudden unrecorded stalling and re-starting immediately can be interfence, the TDC sensor, bad wiring connection, or the injection computer itself. We have had many interference problems on Renault vehicles, caused simply by incorrect spark plugs. In my experience Renaults can be very fussy when it comes to spark plugs, and if someone has fitted even what are normally considered good plugs like say NGK or Bosch, these can often create problems that disappear immediately the correct Renault plugs are put in. So we often got cars in with faults where the car had recently been serviced and non-approved plugs fitted, and then the problems started. Once we changed the plugs back to Renault approved plugs, the problems stopped. So the first question is: have you Renault approved spark plugs? Has anything been changed just before the problem started? Was any work done, just before the problem started? These are the first things to examine. I have seen a similar problem on the V6 which was caused by a faulty TDC sensor, but they are a pig to get at and check or change unfortunately. Well, I should say that when I bought the car, previous owner already told me of the problem which happened some times. I have just had the car in a very expensive reparation at an official Renault garage, and they have replaced, among other things, spark plugs. And car behaves the same. This and the exact sync with the engine temperature makes me doubt about interference causing troubles. Quote Your engine is the L7X which is often pared with the LM0 auto gearbox, and there is a supplement for just that combination. It was not part of the original file. However, there may be some parts of the original file that will still apply. So if you really wanted to get all the information on your vehicle, you would need all the relevent parts of the Dialogys system - not easy when I don't think Renault will sell it outside their franchises. Was there something specific you wanted José? Yes, all ECU related info :) Quote And in answer to your question about coolant level, it should always be checked cold preferably after an overnight stop so it really is cold. Roy OK, so it is fine!. I was afraid thay could have overfilled circuit (mainly because it had a leak in heater matrix and overpressure is for sure bad in these cases!) Thanks again and best regards, JOSE PS: please, take a look at my WEB on: http://jvgavila.com (http://jvgavila.com) if you are curious about my electronic and car hobbies ;) Title: Re: Engine stalling Post by: Lennart Sorth on July 20, 2007, 12:26:38 am PS: please, take a look at my WEB on: http://jvgavila.com (http://jvgavila.com) if you are curious about my electronic and car hobbies ;) Hey! another Mac and tube freak! Using modern components, I built this dual monoblock 14W PP EL84 amp many years ago: (http://www.sorth.dk/tubeamp2.jpg) still my preferred amp, - and on my desk I have (and frequently use) a G4 Cube - 450Mhz passively cooled beauty. :-) On my 2.2dci Espace I had a failing TDC sensor, which stalled the engine occasionally. Actually I think it was the wiring/connectors that were at fault. Now we have an intermittent annoyance with the coolant level sensor, which occasionally (and wrongly) claims we're low on coolant. I think an air pocket plays a role. Trouble is, I cannot even FIND the bloody level-sensor, the only one I suspect is the one, sits in a silly T-junction, where it will be an easy target for air-pockets. Could trapped air be playing games with you too ? /Lennart Title: Re: Engine stalling Post by: roy4matra on July 20, 2007, 02:02:34 am Hello Roy, Thanks a lot for your interesting answer!. Well, I should say that I have done some electronics work on my 2.0 TCT Citröen XM and that I have a very well equipped lab at home :D so I am not scared about sensors and such ;D [big snip] Thanks again and best regards, JOSE O.K. José, now I have an idea of your level of expertise, I can understand what you seek (most owners would not understand). However, I can tell you now that the service manual will not provide the information you require, sorry. Often even the information they provided for us RTE's was inadequate for those that could understand any of it. It was as if they assumed a certain level of knowledge was all the RTE's possessed and they wouldn't let you have anymore even if your interlect was above the norm. Only the wiring diagrams will give you all the injection ECU connection data and I no longer have access to that data. They usually have a 55 pin connector and the red wires carry 12v to power the computer (often 2) black are always earth and yellow ignition feed. The injectors are earth switched and the power supply to them is a reduced voltage (5v). All sensor connections to the ECU should be able to be traced from the colours of the wiring. You have a knock sensor as well as oxygen sensors, the sensors we have already mentioned, as well as inputs from the ABS and auto gearbox computers and connections to the air con. too, so unfortunately unless you can get a wiring diagram it would be a long job to trace them all. I'll see if I can find anything but I'm not hopeful, sorry. Roy Title: Re: Engine stalling Post by: tka on July 20, 2007, 03:15:57 pm Quote I'll see if I can find anything but I'm not hopeful, sorry. Hi Roy, if anything turns up I'm also migthy interested :) Jose, you might be able to read some engine sensor data via 16 pin connector using standard ODBII scanner. The espace is not good at returning ODB error codes (due to more or less intended bugs in the system AFAIK). However, as for the online sensor data, I'm able to see - using and ElmScan Tool - the following ECU and sensor data: Absolute Trottle Eng. RPM Vehicle Speed Timing Adv. - Cyl 1 (signal somewhat suspect though) Intake Manifold Pressure Fuel System Status (closed loop or not) Short Term Trim Long Term Trim Intake Air temp. Coolant Temp. O2 Sensor 1 O2 Sensor 2 One of the O2 signal being a little suspect too (maybe not strange, since I now of only one sensor - right before Cat - beeing fitted to the car??) I've got the 2.016V engine and not the V6 24V as you... BR /tka Thomas Kjćr-Andersen, Esp. 2.016V, 2000 Title: Re: Engine stalling Post by: José V. Gavilá on July 20, 2007, 07:39:40 pm Hello Roy,
Thanks for your message! O.K. José, now I have an idea of your level of expertise, I can understand what you seek (most owners would not understand). However, I can tell you now that the service manual will not provide the information you require, sorry. Often even the information they provided for us RTE's was inadequate for those that could understand any of it. It was as if they assumed a certain level of knowledge was all the RTE's possessed and they wouldn't let you have anymore even if your interlect was above the norm. Only the wiring diagrams will give you all the injection ECU connection data and I no longer have access to that data. They usually have a 55 pin connector and the red wires carry 12v to power the computer (often 2) black are always earth and yellow ignition feed. The injectors are earth switched and the power supply to them is a reduced voltage (5v). All sensor connections to the ECU should be able to be traced from the colours of the wiring. You have a knock sensor as well as oxygen sensors, the sensors we have already mentioned, as well as inputs from the ABS and auto gearbox computers and connections to the air con. too, so unfortunately unless you can get a wiring diagram it would be a long job to trace them all. I'll see if I can find anything but I'm not hopeful, sorry. Roy OK, thanks for your help... let's hope something arises :) ! LATEST NEWS Well, after several days of completely repetitive behaviour (as commented in former messages), yesterday I filled up the tank with the usual 95 RON petrol...... to my big surprise, today, both times I have started the Espace from cold (in the morning at 8:30 and at about 16:00h), exactly the same as other days and with a similar outside temperature (25C in the morning, 30C later), engine has NOT done its usual thing. I know there have been just two isolated checks but I wonder if it could be related with the tank filling... I had never observed this (or, could be, didn't notice >:( !). Again, it could be just an isolated thing... but I am really wondering ???! Best regards, JOSE Title: Re: Engine stalling Post by: José V. Gavilá on July 20, 2007, 07:49:00 pm Hello Thomas,
Jose, you might be able to read some engine sensor data via 16 pin connector using standard ODBII scanner. The espace is not good at returning ODB error codes (due to more or less intended bugs in the system AFAIK). However, as for the online sensor data, I'm able to see - using and ElmScan Tool - the following ECU and sensor data: <big snip> I've got the 2.016V engine and not the V6 24V as you... GREAT!!!. This is one of the things I had in mind, ODB2!. My Citroen XM has an older kind of ECU but it has one advantage: just with a switch and a LED you can read error codes!. I have done it perhaps a hundred times ;) Well, I recall I got some kind of ODB2 kit I never assembled as I had no use for it... will check and, if I not locate it, will try to source a cheap one (hints, please?) I will for sure ask more things regarding this :D ! Best regards, JOSE Title: Re: Engine stalling Post by: Anders Dinsen on July 21, 2007, 07:53:46 am Only the wiring diagrams will give you all the injection ECU connection data and I no longer have access to that data. I've got a diagram here of your car in a paper manual from which I can make scans. I got it off eBay some time ago. Let me know if you need it. One of the O2 signal being a little suspect too (maybe not strange, since I now of only one sensor - right before Cat - beeing fitted to the car??) Hej Thomas I think your car does have two oxygen sensors, in fact I just checked the diagram and it agrees. One is probably sitting after the cat, but I'm not sure. I never had any luck reading OBD from my Espace's and usually revert to my preferred garage to diagnose the V6, but this is interesting. - Anders Title: Re: Engine stalling Post by: tka on July 21, 2007, 09:35:26 am Hi A. & J.
...Yes, after the cat. That's where I looked for it too. It would be a 'standard setup', and it would explain the rather steady readout from that one. However, nothing visible form outside. Could it be more or less built into the cat?, - but then I should at least be able to spot some wiring etc.? BUT the more I'm thinking about this: You must be right, it *must* be there. I'll have to go for a closer investigation. ??? (do your V6's have two O2-sensors?) About the ODBII readout: My car is a 2.016V from Germany. First registration january 2000, i.e. probably produced late 1999. I use an ElmScan 5 (usb), and with that scanner I'm able to obtain resonable answers to many mode 01 PID's (i.e. mostly real time sensordata). Unfortunately the willingness Espace terminates, when asked for mode 03 stuff (which is stored error codes, amongst others). Obviously, I won't tell me either to which ODB standard it conforms (asked directly by 011C) >:( (Anders, since I know from earlier, that you probably live not that far from me (Hundested, DK), then you're of course welcome to drop by some day, and we can test the Elm-scanner on your car) It would of course be migthy insteresting whether the Espace would in fact be able to return error codes etc., using generic scanners, if one just knew exactly what to ask for. ::) BR /tka Title: Re: Engine stalling Post by: tka on July 21, 2007, 10:09:35 am Quote My Citroen XM has an older kind of ECU but it has one advantage: just with a switch and a LED you can read error codes!. I have done it perhaps a hundred times Yes, Jose, those were the days! - Did eventually let my own XM 2.0 CT go just some weeks ago (to a friend, though - yes, I know, never do that ;) -, so we had to get rid all winter and springs error codes, to get suspension back to right...) BR /tka Title: Re: Engine stalling Post by: roy4matra on July 22, 2007, 01:38:23 pm Quote I'll see if I can find anything but I'm not hopeful, sorry. Hi Roy, if anything turns up I'm also migthy interested :) O.K. fine. Quote Jose, you might be able to read some engine sensor data via 16 pin connector using standard ODBII scanner... One of the O2 signal being a little suspect too (maybe not strange, since I now of only one sensor - right before Cat ... I've got the 2.016V engine and not the V6 24V as you... Two things. Renault never seemed to stick to using the OBD codes as all manufacturers are supposed to! In fact many times it simply never worked at all, and when I complained to the management that Renault were not obeying EEC regs. I was simply told 'tough'. Second, there are two oxygen sensors. One before and one after the Cat. Roy Title: Re: Engine stalling Post by: tka on July 23, 2007, 08:09:12 am Quote Two things. Renault never seemed to stick to using the OBD codes as all manufacturers are supposed to! In fact many times it simply never worked at all, and when I complained to the management that Renault were not obeying EEC regs. I was simply told 'tough'. Yaeh Roy, I've heart this story before. It seem's clearly that Renault is not going to tell, how to speak with our Espace's. Guess we'll have to try figuring out ourselves then... ;D In my case the generic scanner is at least able to connect to the ECU, and to retreive reasonable values for most realtime engine sensor data. Allthough not being that much into low level electronics, I think this suggests some level of hardware compatibility? I still wonder whether getting other interesting data, is just about putting other (undocummented) codes into the system... About the second Ox sensor: Was under the car to do some around-the-cat-area pictures. Wouldn't one imagine the Oxygene sesnor to be easily spotable??? (http://www.atelier-amalie.dk/images/esp_ex_l.jpg) (http://www.atelier-amalie.dk/images/esp_ex_r.jpg) BR /tka Title: Re: Engine stalling Post by: roy4matra on July 24, 2007, 02:02:26 am Quote Two things. Renault never seemed to stick to using the OBD codes as all manufacturers are supposed to! In fact many times it simply never worked at all, and when I complained to the management that Renault were not obeying EEC regs. I was simply told 'tough'. Yaeh Roy, I've heart this story before. It seem's clearly that Renault is not going to tell, how to speak with our Espace's. Guess we'll have to try figuring out ourselves then... ;D In my case the generic scanner is at least able to connect to the ECU, and to retreive reasonable values for most realtime engine sensor data. Allthough not being that much into low level electronics, I think this suggests some level of hardware compatibility? I still wonder whether getting other interesting data, is just about putting other (undocummented) codes into the system... About the second Ox sensor: Was under the car to do some around-the-cat-area pictures. Wouldn't one imagine the Oxygene sesnor to be easily spotable??? BR /tka Oh sorry, there *should* be a second sensor! Must be just before the change over happened... Roy Title: Re: Engine stalling Post by: Lennart Sorth on July 24, 2007, 10:58:20 pm Roy - how nice to see that avatar, - almost like reading our MECUK magazine :-)
/Lennart Title: Re: Engine stalling Post by: roy4matra on July 25, 2007, 08:12:35 pm Roy - how nice to see that avatar, - almost like reading our MECUK magazine :-) /Lennart Well I thought since I already have my car shown on my website, I could use that old magazine mugshot so non UK members or residents might see who was giving out various information! To get back on topic, there are a couple of things you might want to check José. First, the idle control valves themselves are not the most reliable of units, and as they are a sort of stepper motor, maybe during the warm up phase, it is not reacting correctly. Second, the power steering switch can effect the idle - when you turn and therefore increase the loading on the engine via the power steering pump, the increase in pressure is supposed to signal the inj. computer to increase the revs. slightly. Actually on later systems it doesn't actually increase the revs. anymore but widens the inj. pulse to give the same effect of stopping the revs from dropping. Now you mentioned that it tried to cut out when you were turning, and you had difficulty steering, so it just made me wonder if it always happens when you are steering during the critical warm up period? If it does, maybe the fault lies in that signal or lack of? That may explain why it didn't happen the other day after filling. Maybe you were not turning at the critical time? The other thing that could affect idling is the fuel vapour carbon canister operating solenoid. If this operates inappropriately it could cause stalling. Or if the canister was saturated it might create too rich a mixture just at the wrong moment. Regarding the re-filling of the tank, have you noticed a vacuum when removing the cap? Try running without the cap on a few times and see if the fault still happens. Finally for now, have you actually taken the 55 pin plug off the computer? A common problem on these cars was water getting in to the loom and running down to the connector where it caused corrosion in the connections. This can cause all sorts of problems depending on which circuits are affected. Roy |