 | Home > Puma (Tdci) > Eratic Idle especially when cold |
 
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| B4Lamb Member Since: 21 Mar 2015 Location: Abergavenny, Wales Posts: 233   
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It sounds like it is working although as you say it may not be moving the valve itself either fully open or closed during normal operation. One of the known failures is the small pinion gear on the end of the motor shaft loses its friction grip and so the motor turns but the gear doesn't. If I heard the cleaning cycle myself I could probably detect or not if the motor is indeed turning all three gears in the chain or just the motor is spinning. It's a possibility!! The fault code diagnose is not always that precise as it uses several measurement to come to its likely conclusion that there is an EGR problem so I would not take it as red but it's pointing you in that direction. Best to get the thing out and test it on the bench, albeit a bit of a
 to do. "You are never to old to learn something new" |
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24th Sep 2017 11:57am |
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| B4Lamb Member Since: 21 Mar 2015 Location: Abergavenny, Wales Posts: 233
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Hi OleDave,
Now this is interesting for a couple of reasons. The EGR is not supposed to operate when the engine is cold because the NOx is not created until the combustion reaches very high temperature so EGR is supposed to be suppressed. So assuming it is suppressed initially and your fault kicks in later when the engine temperature is raised you possibly could attribute the fault to the EGR when it starts to be activated. I don't honestly believe it is due to the EGR but since you are not experiencing the problem when cold when the EGR closed then it is definitely worth pulling the plug out of the EGR so that it never opens. If your fault does not develop then yes the EGR is the culprit however if it develops again then I really cannot see its the EGR. I know you want to change the EGR to eliminate it and if the first scenario manifests itself then you would be justified in replacing it however, if the latter occurs you may be just changing it for the sake of your garage mechanic. Regarding the SVC I would not be to harsh on your mechanic as how would he know a replacement is faulty. They have very fine tolerances and he would not of even dismantled the new one to inspect it before fitting and even if he did he would not spot anything unusual. Your anger should be directed at the SCV manufacturer "You are never to old to learn something new" |
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24th Sep 2017 9:30pm |
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| OleDave Member Since: 19 Oct 2013 Location: CARDIFF Posts: 175  
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Hi B4lamb, again many thanks for the input, haha I have no anger at the mechanic or the garage as they are like family to me, I also know from experience that when fitting a new componant its impossible to determine a on a new item if its faulty or not unless its obviously damaged.
From reading all the replies over the period I have had re this problem and with your latest posts, to me the problem still has all the hallmarks of a faulty fuel vapour valve, the only unknown at the moment is the EGR valve and its sensors, I have seen some very odd problems in the past which point to a specific problem finally found to be something else?... I think I will speak with my dear friend today in the garage and run by him your thoughts, I will then disconnect the EGR valve and try it for a while to see what the result is, even if the engine management light does flag up and stay on I can always drop into the garage and have the error code cleared. Many thanks for all your help, will let you know the result of the garage conversation and the disconnection, if the result helps others with a similar problem thats a bonus. Regards Ole Dave |
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25th Sep 2017 7:45am |
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| B4Lamb Member Since: 21 Mar 2015 Location: Abergavenny, Wales Posts: 233
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Ok, good luck oledave. "You are never to old to learn something new"
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25th Sep 2017 8:04am |
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| OleDave Member Since: 19 Oct 2013 Location: CARDIFF Posts: 175
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Hi B4lamb, yep its me thinking out loud again here, have just spoken to the garage on the blower and the owner has suggested taking it back to them and they will plug it in to see if the EGR fault has returned, I intend to do that this afternoon, then discuss then the options from there.
I am not sure if you have ever done this or if its a possibility? it crossed my mind that while the diagnostic is coupled and the EGR fault cleared thats if its there again? if I sit there watching the screen with the engine running, when it does starts to idle eractically! I wonder if the fault on the EGR coincides with the eratic idle return and would it be flagged on screen when occures? have you ever tried that? Regards Ole Dave |
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25th Sep 2017 10:16am |
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| B4Lamb Member Since: 21 Mar 2015 Location: Abergavenny, Wales Posts: 233
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Hi OleDave,
I think that the ECU only generates the fault code after about 3 consecutive occurrences of the fault for non critical faults so you have to keep stopping and starting the engine. I'm assuming it does this such that random glitches and occasional misdiagnosis does not trigger a fault and illuminate the MIL as it may be false alarm. I could be wrong but others on this site may be able to correct me or validate it. Let me know what fault code it comes up with. "You are never to old to learn something new" |
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25th Sep 2017 11:28am |
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| OleDave Member Since: 19 Oct 2013 Location: CARDIFF Posts: 175
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Hi B4lamb, your correct on the point of the diagnostic equipment does not give you a live view of faults as they occur as I have just come home after a visit to the garage, the faults only show after an engine turn off and back on, only then are they displayed on their Bosch diagnostic equipment, anyway they coupled up their diagnostic computer and ran through the programme, as before if flagged up the EGR valve ( Sorry I do not have the error code) following that they put the engine on a live graph showing engine performance at various throttle conditions and what it did flag up were flat spots during throttle up!! also the eratic idle showed up once and only once while the tester was sat in the car, the concensus of opinion is that the EGR is the cause!
In a discussion after with my long term friend and owner of the garage he is convinced that the symptoms can be related to EGR faults as he has winessed them all before many times with the 2.4 Transit engine, ie Flat spots, irregular idle speeds, lack of power, even cutting out, the only route seems to be to change the valve and see what the result is? no other faults were identified at that time that could be recorded via error codes. So, the plan is my lovley girl is going in soon as they need to strip off the valve to get a part number from it to be 100% sure for compatability, a new valve fitted and hopefully a cure to this long standing annoying problem, will let you all know the outcome in the hope it will assist others with a similar problem. Regards Ole Dave |
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25th Sep 2017 12:21pm |
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| jst Member Since: 14 Jan 2008 Location: Taunton Posts: 8010  
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this all sounds pretty similar to mine and the eratic idle, i am going to disable the EGR and see if that solves it as my first step, will then look to VCV and Pressure valve. Cheers
James 110 2012 XS Utility 130 2011 M57 bespoke Camper 90 2010 Hardtop 90 M57 1988 Hardtop |
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25th Sep 2017 7:17pm |
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| OleDave Member Since: 19 Oct 2013 Location: CARDIFF Posts: 175
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Hi James, this problem with eratic idle I have had on and off for about 18 months, to be fair the forum in the early days when I noticed it first all pointed to the Fuel vapour valve (SVC) oddly it only did it when the weather was cold but that was put down to the clearance being tighter, it cleared as the the engine temp lifted , so I lived with it but as time went by it became more of a regular feature and on occasions it started to cut out, I also had delays when throttling up from a standing start and the throttle response became slower.
The valve was changed and put on a diagnosic set up to clear any faults, at that time the computer flagged up an EGR fault but was cleared during the test, all seemed wonderful as I drove away from the garage smiling my face off, it had smoother gear changes, no delays on throttle up, no jerking after slowing down and then throttling up, that is !!! until I neared home and the engine cut out at the traffic lights, after starting it the poor throttle response was back as bad as before and the eratic idle returned. Back on the diagnostic equipment it again flagged up the EGR valve even though it appeared to be going through the cleaning cycle, no other error codes were recoded. The opinion is from some members with vast knowledge of the Defender that its unlikely that the EGR would cause engine shut down or eratic idle and I agreed as I have never seen that problem myself on other makes of cars fitted with EGR valves, however, its the only item showing an error code at the moment so the route is to change it when the new valve arrives, with finger and toes crossed I just hope that it solves the mystery. ( The Suction control valve has no error code to flag up by the way James ) The one thing I am going to try over the next few days is to disconnect the EGR from the wiring loom and just see what happens, ok the engine managment light no doubt will flag it up but that will not matter for the moment, will post on here the result of that and the results of changing the EGR when completed, if its that hopefully it will help others like yourself to get to the solution quicker and cheaper and I will get shot of my annoying problem finally. Regards Ole Dave |
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26th Sep 2017 7:36am |
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| jst Member Since: 14 Jan 2008 Location: Taunton Posts: 8010
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i am hoping mine is the EGR and blanking it will sort the issue, should know tomorrow or Thur! fingers crossed for us both! Cheers
James 110 2012 XS Utility 130 2011 M57 bespoke Camper 90 2010 Hardtop 90 M57 1988 Hardtop |
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26th Sep 2017 6:24pm |
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| OleDave Member Since: 19 Oct 2013 Location: CARDIFF Posts: 175
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Hi guys, at last the problem with the erratic idle has been solved, I will try to keep the events leading to success as concise and brief as possible as it turned out to be a bit of a fiasco getting there.
The erratic idle first appeared in July 2014 when the weather got colder and would disappear when the engine got hot or the weather became warmer which was as many pointed out, was a typical SCV problem. Recently the erratic idle became much worse with the engine cutting out constantly at idle, the Landy went into the local garage and the SCV was changed, during the clearing of error codes it was noticed the EGR also flagged up a fault? but was erased as a one off episode, after leaving the garage the engine ran perfectly for 12 miles, then cut out, the erratic idle returned with renewed vigour. The following day I returned to the garage and the Landy was plugged back in to the Bosch diagnostics where again a fault on the EGR was flagged up, no other error codes were recorded? At this point the garage were convinced the EGR was producing the erratic idle as they had fitted a New SCV the day before and from their experience with 2.4 Transit's had seen this problem previously many times and the EGR was found to be the culprit for the erratic idle and flat spots. A new EGR valve was ordered, in between ordering it and its delivery many discussions were held with B4lamb who has a vast knowledge on control systems and I am truly grateful for his much valued help. B4lamb during this period pointed me in the direction of a Bluetooth OBD2 adaptor and the Torque Pro programme which is downloadable from Google play store, on receipt of the adaptor and programme I set about following B4lambs recommended checks and reporting back what I was seeing. Being unfamiliar with the Torque Pro I fumbled around for a while not knowing how to get the most out of the Torque Pro figures, one check that B4lamb suggested was to disconnect the EGR and record the result, with his vast experience his view was that if disconnected and the engine still ran erratic we could discount it, sadly due to the terrible weather I could not carry out the check, but it should be noted by others to try that if they have similar problems or suspect the EGR of causing a possible erratic idle. During one test with the Torque Pro I noticed that the fuel rail pressures at idle, when I could get the engine RPM stable!! were very erratic, the figures varied between 1400psi to 4500psi and on occasions higher, the conclusion was that the variation could possibly be due to a chicken or egg situation, as the high pressure fuel pump is driven by the engine, was it a case of .....does the fuel pressure drop causing the engine to stutter, or was it the engine stutter causing the fuel pressure fluctuations? The Landy was returned to the garage after receipt of the new EGR and fitted, all error codes were cancelled following fitting. The result..........the engine was still erratic at idle which proved B4lambs thoughts, and my gut feeling during the process that the EGR was not the cause but was still a faulty SCV? At this junction, why Land Rover never incorporated an error code into the engine management system for an SCV fault beggars belief as its a major control item? The garage then fitted a second new SCV, result......... the erratic idle problem ceased immediately after all error codes were cancelled. Conclusion. I would suggest to all members to obtain an OBD 2 blue tooth adaptor and the Torque Pro as it proved to be a valuable asset to help highlight problems which are associated with SCV failure especially erratic fuel rail pressures which are a good indicator. If after changing the SCV you still experience an erratic idle, disconnect the EGR as advised by B4lamb, if the idle is still erratic with the EGR disconnected its more than likely to be the SCV giving the problem even if its a brand new valve, the EGR error code flagged after disconnection can be cancelled with the Torque Pro I hope I have covered all the main aspects of the problem and it will be of help to others in solving an erratic idle on the Ford Duratorque engine, hopefully without all the trauma I have been through. I am sure if I have missed any important point or issue, B4lamb will willingly elaborate or correct any errors I have made in this posting to the forum. Finally, many thanks to all members for their help, but a very special thank you to B4lamb for all the information, his unending patience with me, and his much valued experience and time in helping me get to the resolve of the problem with the Defender 2.4 engine control system, I am much wiser following his advice. |
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6th Oct 2017 4:32pm |
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| Nevillerover Member Since: 14 Feb 2015 Location: Suffolk Posts: 224 
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I am leaving the house in next half hour to go to garage for diagnostics for erratic idling, hunting and stalling so this is really relevant to me.
Please someone explain what and where the SCV is so I can mention it when I get there. I haven't got time to research it before I go. |
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7th Oct 2017 7:50am |
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| OleDave Member Since: 19 Oct 2013 Location: CARDIFF Posts: 175
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Hi Nevillerover, the Fuel vapour valve (SCV) is directly behind and below the main fuel pump on the nearside of the engine space, it can be removed without removing anything but its a lot easy to get at with the inlet manifold removed, you will see a wiring connection attached to it, any help? sounds typical of a fuel vapour valve failure with your symptoms which were similar on mine?
Regards Ole Dave |
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7th Oct 2017 8:55am |
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| OleDave Member Since: 19 Oct 2013 Location: CARDIFF Posts: 175
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Hi Nevillerover see pic of SCV item 2 on the picture
Regards Ole Dave |
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7th Oct 2017 9:12am |
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