broken down

[richardmorris]

Hello all,

I've just had a call from my Dad, my E320 coupe has failed to proceed. Felt like it was running out of fuel then conked out. Restarted and pulled into a layby. Conked out again. Then restarted and had it idling for 5mins perfectly so continued on to Chester where it cut out again. It has half a tank if fuel.

It is currently running and they're trying to take it to mercedes chester for help.

I fitted a new fuel relay (green one ) the other month as it was occasionally not starting after a long journey. It was fine since.

Any ideas anyone? Seems to me it could be the fuel pump, wiring loom (or OVP relay - could that cause this sort of problem?)

Thanks

 

[television]

If it is the relay for the fuel pump you can pull it out and short out pins 7 and 8, this will make the fuel pumps run all the time and an easy way to test to see if the pumps will run, there are sometimes 2 and if one stops no fule much will get through.

 

[EmilysDad]

....

Any ideas anyone? .....

I've no idea abou your specific engine, but it sounds like the classic symptoms of a failed/failing crank shaft sensor :-?

 

[richardmorris]

Could be I suppose, (assuming it has one??), I know the citroen CXs I'm more familiar with had the crankshaft sensor as a recommended glove box spare.

 

[grober]

Could be an engine wiring loom problem if it hasn't been changed yet. They have crankshaft position sensors but these are not known for failing- however its an old car?? Are you sure you got the correct fuel pump relay?

 

[richardmorris]

Fuel pump relay from Parts for mercedes using VIN number. looked the same to be honest, and it's done a fair few 100 miles since then.

I "think" the looms been done - no paperwork when I bought the car but had a full stamped history. Could be though - presumably the worst case scenario!

 

[grober]

Other thing is the FPR requires an engine running signal or it switches off. Other possibilities are a faulty ignition switch or immobiliser

 

[richardmorris]

Other thing is the FPR requires an engine running signal or it switches off. Other possibilities are a faulty ignition switch or immobiliser

Well I immobilised the immobiliser permanently last year as it wouldn't resync after a battery change.

The update on the car is that it's currently at the main dealer and they are going to call my Dad this evening. It didn't get there under its own steam though as it conked out again outside the Abode restaurant next to the racecourse -if you're going to spend a few hours waiting to be rescued then a michelin * restaurant isn't a bad place I suppose!

Will keep you all informed.

Richard

 

[richardmorris]

Update.

Well it's run fine for the mechanics at the dealer during a couple of road tests yesterday and today! They did say they've tightened and cleaned contacts on a couple of relays though.

They don't think it's the loom as it's running perfectly smoothly and revving cleanly.

They're keeping it for a few days to give it a going over.

Typical though that intermittent faults never show up for mechanics!

 

[kth286]

One of those may have been the Overvoltage Protection Relay (OVP relay), which can go bad.

 

[television]

The OVP relay usually causes rough running and the ABS lamp would have been on in most cases

 

[richardmorris]

Final update.

My Dad's just picked it up from the dealer and says it's running very smoothly.

Service manager very apologetic they couldn't pinpoint the fault although he said when it was running and they touched the fuel pump contacts it was stuttering.

Had several really good road tests. They only had it so long because my parent's were away.

£73.32 for labour including diagnostic £87.98 altogether. So all praise (if that's allowed? ) for Mercedes-Benz Chester.

He did say he could have sold it on the forecourt too.