Another Diesel non runner

[Tigertonito]

Hi,
I have a 2003 saloon which I bought about 2 months ago. It currently has half a tank of fuel in it.
A week ago I was driving home when it cut out on me and wouldn’t restart with the key. I was on a hill at the time so tried to bump it but it still refused to restart.
Pulling up at the side of the road, I started checking through the Haynes manual for fault finding. After about 5 minutes I thought I’d give it a go with the key again. It started but then died after 10seconds or so. It refused to start again for 5 minutes so I phoned the breakdown company. While I was waiting, I managed to start it but the same issue happened again (10seconds of life before dying and unable to start it for another 5 minutes)
I noticed the noise to the under bonnet pump wasn’t there, when the mechanic arrived I mentioned it to him and he took off the pipe leading from the pump while I cranked the engine. Sure enough no fuel came out. While fiddling with the leads however it did flicker into life momentarily but then stopped again and we couldn’t get it to repeat it. He took off the connector to the fuel pump and found it was full of diesel.
Before this I hadn’t had an issue with the car, except for an occasional “hot smell” like an electrical/oily smell and the near side front indicator bulb sometimes not working but usually sorting itself out on the same journey.

I read that the pumps are common problems on these and clearly it was leaking into the connector so I bought a new pump, and fitted it. - didn’t fix it. Subsequently I used a direct 12v feed and both the new and old pump both work when it’s applied.
Relay in bonnet fuse box- I noticed this was warm after cranking the engine. I wasn’t entirely sure it was working properly so I swapped it for the identical rear windows one which I knew worked.

Once I swapped these round, I tried to start it again. When I got the key to second position the cooling fan turned on immediately and the engine temp gauge went to maximum with the orange led illuminated. Clearly it wasn’t hot as it had now been on the drive for a few days. It would turn over but wouldn’t start while turning over the temp gauge returned to cold and eventually the fan would switch off.

I took the ecu out, there was about half an inch of water in the chamber. Not enough to reach the bottom of the ecu housing but may have been slowly draining over those days. Plenum now cleared out. One of the screws to the ecu looked a little rusty but others were sound. Opening up the ecu it was dry but there was a tiny bit of corrosion on one of the circuits which was gently brushed off with a toothbrush. The battery then decided to give up trying to start it.

All the fuse connectors were removed (from underneath the bonnet fuse box) the ecu was left near the radiator overnight just in case and was then reinstalled and the battery was charged for 24hours on a trickle.
Now when I try to start it, I can hear the under bonnet pump kick in, the temperature reads normal but the car still won’t start.

I don’t think I’ve ever heard the in tank pump make a noise.
I thought it’d be the under bonnet pump or power to it after the recovery guy showed that it wasn’t working but both of these seem to be working now.

Any ideas?

[Arctic]

HI Anthony
The ECU as been for a swim by the sound of it, therefor in my opinion is get it sent off to one of the T4 gurus' Brian or Russ and they will get you sorted.

I am sure they will be along before today is out and give you the advise you need, and will soon have you back on the road.

[BigRuss]

It does sound like it has been for a swim at some point unfortunately.

If you'd like me to have a look at it, I can try it for you and if needed have service replacement units.

Drop me a p.m. if you wish to send your ECU.

Russ

[Tigertonito]

I sent the ECU off to russ to be checked over.... it came back as working properly.

with the ignition on I read 12volts coming out of the glow plug relay. Every fuse and relay was checked in both glovebox and under bonnet fuseboxes - all ok.

This all led to a conclusion of a wiring problem to be most likely. Unfortunately I then ran out of time to continue my own diagnostics. I had to go back to work but most importantly, the kids went back to school and i could no longer use the partners car. As I'm new to this it would have taken me a long time to find each of the pins and where they go to, to check for continuity till i find the break (assuming just one).
I therefore stuck it in the garage, explained the issue to them and what i'd done/ruled out, and got a hire car for a week.

Long story shortened..the first garage had to tow it to an electrical specialist as they couldn't work out the problem. Another week of hire car

I phoned them up friday as I'd had no word. They'd begun unplugging and checking the fault codes on the ecu... tried to keep telling me it was the ecu but as I knew it worked with Russ I kept saying it wasn't that issue.

Phoned again monday, it had apparently started and filled their garage with smoke (which confirmed the ecu was ok).

Phoned again tuesday (today) as the hire car was due back. They'd disconnected the EGR which was full of carbon. the large patch of soot on the floor was shown as evidence. he wanted to keep it in for another few days to check what the issue was, as he wasn't sure why it had restarted. All he'd done was disconnect and reconnect the wires to all the components showing up as faulty on the ECU. He'd tried wiggling all the wires to generate the same fault but to no avail.

I figured if it was working I could do with it for work instead of paying out for a hire car for a third week so I went and picked it up, starts first time at the moment but there must be an issue lurking somewhere still. There wasn't any smoke when I picked it up and I did 20 miles on the motorway at high revs too but still no hint of smoke.
The EGR remains disconnected and needs to be cleaned thoroughly/bypassed before i reconnect it.

It might pay to have a replacement wiring loom on hand in case it was a break (not just a poor contact) which rears itself in the near future.

[macafee2]

which part of the wiring loom are you considering replacing? unless its a short length you will be amazed how many plugs and terminations a wiring loom can have and replacing a large one, is no easy task. Not a job I'd recommend.

macafee2

[slovcan]

Originally Posted by Tigertonito

They'd begun unplugging and checking the fault codes on the ecu...

Phoned again monday, it had apparently started and filled their garage with smoke (which confirmed the ecu was ok).

They'd disconnected the EGR which was full of carbon. the large patch of soot on the floor was shown as evidence. he wanted to keep it in for another few days to check what the issue was, as he wasn't sure why it had restarted. All he'd done was disconnect and reconnect the wires to all the components showing up as faulty on the ECU. He'd tried wiggling all the wires to generate the same fault but to no avail.

I figured if it was working I could do with it for work instead of paying out for a hire car for a third week so I went and picked it up, starts first time at the moment but there must be an issue lurking somewhere still. There wasn't any smoke when I picked it up and I did 20 miles on the motorway at high revs too but still no hint of smoke.
The EGR remains disconnected and needs to be cleaned thoroughly/bypassed before i reconnect it.

Fixed! Drive it and enjoy it. It might be years before that ever happens again, if ever.

It sounds to me like it was a bad contact at a plug which was cleaned by the simple act of unplugging it and reconnecting it.

The clogged EGR would really hurt performance. Just dumping out all the soot that the garage dislodged would have improved performance immensely compared to completely clogged. Clean it and reconnect it or fit a bypass.

Maybe I'm wrong, but maybe take some time and see how things work out.

Cheers,
Glenn

[BigRuss]

Originally Posted by macafee2

which part of the wiring loom are you considering replacing? unless its a short length you will be amazed how many plugs and terminations a wiring loom can have and replacing a large one, is no easy task. Not a job I'd recommend.

macafee2

The cause of the none starting was caused by a lack of power to the crank, cam, egr and maf sensors which all share a common feed
This was bourne out by the fault codes that I read from the ECU while I had it
The glow plug relay also shares this feed but voltage was present but this feed comes in seperately before the engine loom.
My suspicions are that there may be a problem with the engine loom, while the garages had it they may have disturbed it enough for the poor connection/break to re-establish the feed.
I guess now it's a wait and see if the problem re-emerges if so the most economical solution time and labour wise would be to fit a replacement engine loom, after all you'd have to strip it in order to locate the fault.

It's not the first that we've seen with this fault and it certainly won't be the last

Russ

[marinabrian]

The supply Russ talks about derives from engine compartment fuse No.1 and is a red wire with a white tracer.

It terminates inside the ECM plastic housing in a splice joint, where it is wired in a radial circuit to the glow plug relay on pin 12, the cam sensor on pin 1 fuel pressure regulator on pin 1, EGR on pin 1, and MAF on pin 2.

It is common for the splice joint in the ECM housing to fail on it's input cable from fuse 1, and if I encounter a non starting diesel with multiple fault codes relating to CMP, FP regulation EGR, and MAF, the first thing I do is to poke a piece of wire into pin 12 of the glow plug relay connector, and straight to battery +ve as a test

Brian

[trikey]

Originally Posted by marinabrian

The supply Russ talks about derives from engine compartment fuse No.1 and is a red wire with a white tracer.



It terminates inside the ECM plastic housing in a splice joint, where it is wired in a radial circuit to the glow plug relay on pin 12, the cam sensor on pin 1 fuel pressure regulator on pin 1, EGR on pin 1, and MAF on pin 2.



It is common for the splice joint in the ECM housing to fail on it's input cable from fuse 1, and if I encounter a non starting diesel with multiple fault codes relating to CMP, FP regulation EGR, and MAF, the first thing I do is to poke a piece of wire into pin 12 of the glow plug relay connector, and straight to battery +ve as a test



Brian

It has to be orange wire though otherwise the law isn’t upheld!

[BigRuss]

Originally Posted by trikey

It has to be orange wire though otherwise the law isn’t upheld!

Yes it's the law, carry one around in my bag eveytime I go to a non starter

Russ