2.5td Diagnosis, Lexia check wented

[techmanagain]

An aquaintance of mine is jumping from item to item to try to get a 2.5 started.
As he seems to try everything at once without proper thought. is there some kind soul with suitable diagnostic equipmemt prepared to go and point him in the right direction (For a consideration)?
Located near Juncdtion 25/26 of M1 I understand.

[noz]

Hi techman,

Can you persuade him to join club-xm? I'm sure we can diagnose his problem if he comes here directly and tells us a little about the symptoms and the pre-conditions.

You can assure him we don't bite !

Cheers

noz

[techmanagain]

I wish too that he would join, but at the moment it would not be of much help as he has no computer or email contact bar me, and I have not all that much time to spare to relay every query to this site, so tend to filter his queries and pass on only the tricky ones to the forum!

[xmexclusive]

Direct contact made, will report back on progress.
We have virtually eliminated fuel supply problems.
Now checking wiring and ECU against similar age cars.
It seems the car had the ECU swapped after delivery.
Original ECU was chipped and not part of sale.
ECU currently fitted is from a much older 2.5 and has a different parts code.
This suggests that perhaps the car did not run properly on the current ECU or it would have been fitted before delivery.
Noz's listing of ECU's has been helpful.
Seem to remember "onthecut" posting about one of his 2.5's failing to run properly as a late car fitted with early ECU.

Update: Not having access to the failed car limits what can be done.
Have now identified 6 different ECU/wiring permutations for the VP36 with 2.5 engine.
Wiring diagram cross checking is a pain. That will take a bit of time.
This morning, 26th, I tried a check on the one of my cars with the keypad and ECU code check hardware bypassed. It does not need an unlocked ECU or a start code.
Early type ECU car so fitted a late type ECU. Car failed to start.
Will repeat the process this afternoon but fitting a late type car with an early ECU.

Update: With a late type car fitted with an early ECU starting is very difficult but when it does catch the engine races with no throttle control. This is exactly the state and symptoms on the car that started this post. It seems that the car was sold on in this state. It also explains why nothing that the new owner did cured things. The engine loom wiring on the car was checked out as far as was possible and the mods found corrected. Taking it back to as built seemed the best option.
A late ECU was supplied on loan and when fitted the car played dead so not the immediate success hoped for. This was strange as the ECU was pre tested ok. The new ECU was operating the keypad immobilser to green but nothing else.
We went back to fuel checks by slackening off an injector pipe. That proved key as with the original ECU there was fuel but not with the correct ECU. Took a little while for it to sink in that the correct ECU was not switching the injector pump on.
So then I looked at the list of things the ECU checks and talks too during start up.
The glowplug relay dropped into the frame. At first I dismissed it but then remembered the relay type and engine wiring loom change between early and late ECU type. So the car owner with help from a reputable supplier sourced a replacement glowplug relay. This arrived and was tried with no success. Giving up and scrapping the car seemed flavour of the month. I double checked the new glowplug relay part number and found that an alternative had been supplied. Web checks did not help to confirm that it was a direct replacement. Car owner was given correct part number again and sent scrapyard searching. Car started on first try once the correct relay was fitted. Unfortunately it seems to be running in limp mode so we are not finished yet.

John

This post has been edited by xmexclusive on August 28, 2010 09:48 am