CDTi electrical gremlins - 2 months and counting...

[-TC-]

Hi all,

So, my beloved jalopy (54 plate Contemporary CDTi) has been off the road now for two months after suddenly developing symptoms in which she cut out for a while then restarted after a few minutes - then unfortunately within a day she seemed to cut out for good. Towed to my local garage (who are not Rover specialists, but are technically astute and honest), the fuel pump (single pump setup) was replaced based on the RAC guy's suggestion (and my go-ahead), which seems to have been unnecessary in the event - can only blame myself...

So having ruled the fuel pump out and a few other bits and bobs, I asked Phil-T4 to come and have a look, and as expected the man is a scholar and a gent. The gremlins seem to be exceptionally sneaky in this case however, as after trying 3 ECUs and replacing the crank sensor, we couldn't get any joy. After spending several hours going over the engine electrical systems with a multimeter like the trooper he is, Phil discovered that the yellow/red feed to the ECU seemed to be reading 24 volts. Running a wire from the fusebox live feed to the yellow/red cable meant that the engine finally fired, but this was not a permanent solution as it would have meant the ECU was permanently drawing power.

This next bit relies on my memory, which can be a bit flaky at the best of times, but Phil reckoned this likely meant a poor earth connection somewhere, and I asked the local guys (as it was getting late) to have a look at/clean the earth connections on the A pillar and fusebox when they had time in the next few days. I'd need to find out exactly what they did after that, but apparently they did get her running again for a few hours, duly buttoned her up ready to give back, and - just as they popped the plenum cover back on - she cut out again.

So, this last weekend I went digging in the forum archives to see what I could see, including this thread :

http://www.the75andztclub.co.uk/foru...i+earth&page=5

In which the problem turned out to be corroded connectors under the bonnet fuse box...

and this post from marinabrian:

http://www.the75andztclub.co.uk/foru...73&postcount=7

Which suggested checking the wiring between the ECU and the main relay socket...

So I undid the battery, took out the fusebox and diligently used some switch cleaner on the plugs, plugging and unplugging a few times as described, then put it all back together. Following that I can confirm (presuming I was using my multimeter correctly) that the wiring between the ECU and the relay seemed to be OK (it may have been fine beforehand).

Unfortunately, while the engine did cough slightly when first cranked, I still got no joy. So I tried hooking the positive to the yellow/red as Phil did, with the intention of taking the car to him for another diagnostic, only to find she no longer started with that trick either. Cue my running around like a headless chicken for a few minutes, convinced I'd ballsed something up while trying to sort it...

So then I took my multimeter and checked the voltage going into the red/yellow terminal and unlike the reading in ignition 2 when Phil was down (22-24V), it was reading an even 12V.

Because of this I'm guessing that the garage mechanics cleaning out the earth/nearside fusebox may have solved the initial problem that Phil found (which was why the engine ran for a while) only for another completely different gremlin to surface while she was running.

Apologies for the long-winded description, but I wanted to get all the details in there - I'm at the end of my tether here, the lads in the garage are sick of the sight of my car and I'm all out of ideas at this point. Any suggestions would be gratefully accepted and welcomed.

Many thanks,

TC (Joe).

[eddiemc05]

Sorry your having such a hard time ..
What is single pump setup? It kinda sounds like lack of fuel pressure? But looks like ur guys have checked that already....sounds like phil after having a look already is yr best bet for finding the fault ... is a recover truck an option?

[-TC-]

Originally Posted by eddiemc05

What is single pump setup?

It's a very late '04 car (registered new Jan '05), and it has the newer fuel pump setup (in-tank only, no underbonnet pump as I understand it) - according to Phil, this setup tends to be reliable and doesn't usually need to be replaced, which in turn probably means I've just given myself unnecessary extra expense by getting mine replaced in the beginning. The upside of which is that a faulty fuel pump can be ruled out...

sounds like phil after having a look already is yr best bet for finding the fault ... is a recover truck an option?

It's an option, albeit an expensive one (London - Milton Keynes)... I've had Phil down my way once, and he was a star. I was opening the question to the forum to see if the rest of the folks have any ideas before I have to bother him again...

[marinabrian]

Joe, sounds like a silly question, but does your oil pressure warning lamp illuminate when the ignition is turned to position 2?

Trust me there is a reason behind the question

Brian

[-TC-]

Originally Posted by marinabrian

Trust me there is a reason behind the question

Sir, the likes of Phil and yourself automatically have my trust.

I can't remember off the top of my head, but I'll try to sneak down to the garage tomorrow to find out...

[marinabrian]

Originally Posted by -TC-

Sir, the likes of Phil and yourself automatically have my trust.

I can't remember off the top of my head, but I'll try to sneak down to the garage tomorrow to find out...

Be interesting to see

Let me know what you find please Joe

Brian

[-TC-]

Originally Posted by marinabrian

Joe, sounds like a silly question, but does your oil pressure warning lamp illuminate when the ignition is turned to position 2?

Indeed it does, and stays on...