V220 CDI W638 wont start after short drive.

[Snoop12324]

Hi guys
I've owned this mercedes v class w638 for a while now but over the last few months it's been causing intermittent starting problems that no garage can seem to diagnose.

First start in the mornings never let's me down but after a short drive and parking it up for a while.. whe I come back to start if up.. It cranks but does not fire up.. If I wait for half an hour or so and try again it fires up straight away..

I've changed the:
o rings on the fuel pressure regulator..
The crank sensor
Fuel filter
O rings on high pressure fuel pump
I also had changed the injectors and cam sensor a couple of years ago so don't think the cam sensor could have gone faulty so quick.

Has anyone else experienced this?
I would appreciate any advice you could give.
Thanks Saf

 

[m80]

Cut off relay, engine (management) relay ????????????

 

[DSM10000]

Crankshaft Position Sensor failure can give these symptoms.

 

[MSG2004]

Cut off relay, engine (management) relay ????????????

That crossed my mind as I read the first post here.
Many, many years ago when I had sports vuaxhall car about 34/35 years ago I bought the
1 yr old car. It ran fantastically then after a year, at times trying to start the car from a very warm engine often resulted in nothing IIRC - ie
no sound etc on turn of key IIRC - it was one of those relays. I was lucky I just took it to the main dealer and as I mentioned the problem the man at the reception desk told me to try a relay switch ie a small oblong unit and gave me one to try out and I could return it if it did not work - it did the trick

Edit - my car was petrol, electronic fuel injection

 

[m80]

That crossed my mind as I read the first post here.
Many, many years ago when I had sports vuaxhall car about 34/35 years ago I bought the
1 yr old car. It ran fantastically then after a year, at times trying to start the car from a very warm engine often resulted in nothing IIRC - ie
no sound etc on turn of key IIRC - it was one of those relays. I was lucky I just took it to the main dealer and as I mentioned the problem the man at the reception desk told me to try a relay switch ie a small oblong unit and gave me one to try out and I could return it if it did not work - it did the trick

Edit - my car was petrol, electronic fuel injection

I had similar / same with a BMW 1.8i. If I kept trying, but could be for 1/2 hour, it would likely catch.

 

[Snoop12324]

Cut off relay, engine (management) relay ????????????

Does the w638 deisel have that relay?

 

[Snoop12324]

Crankshaft Position Sensor failure can give these symptoms.

I changed that but did not solve the problem.. this problem only happens on short drives.. never while the car is at full temp and never on first initial cold start only if I've driven for a short journey and parked it for a while

 

[m80]

Does the w638 deisel have that relay?

Dunno, but it must be shut down somehow.