ml 270cdi ecp light

[T BONE]

PLEASE HELP!! my epc light comes on randomly then engine cuts out approx 10 seconds later, I crank the engine for about 10 to 20 seconds then it fires up can run ok for 10 minutes or a couple of days before this happens again....
Things i have done in this order...
fitted new fuel filter, air filter (both from cheap local spares shop)
fitted new maf meter, this brought the car out of limp mode but didnt cure problem.
engine dignostics (snap-on) fault codes i got are
p1470 charge pressure positive control
p0190 bank 4/6 rail pressure sensor (signal voltage too low)
p0100 bank 2/5 hot film map air flow (low voltage)
p1187 rail pressure monitoring pressure control valve closed
I added fuel treatment ran it for a week
cleaned egr valve and checked all hoses, oil and filter change
cut a slot in the exhaust between the 2 cats to see if it was being caused by 2nd cat blockage
And heres the incredible bit...just been on holiday for a week 500 mile round trip all motorway not a single problem, got home put the car on the drive 1 hour later i started the car epc light came on same probs...
Any ideas!!!!!
ml 270 cdi manual 2002

 

[panason1c]

Could be the high pressure pump faulty.

 

[Dieselman]

The rail pressure sensor code is the issue.

Check the pump and the fuel pressure control valve. No1 hit is the valve.

 

[paultredgett]

The rail pressure sensor code is the issue.

Check the pump and the fuel pressure control valve. No1 hit is the valve.

Dieselman.......

could it not be a crank/flywheel sensor etc (magnetic sensor covered in flywheel metallic debris) throwing a negative feedback to the ecu making it partially shut down, only asking as I had the same thing ish on a ford mondeo estate and when I removed the crank angle sensor the magnet was covered in fly wheel debris which I cleaned off and it ran perfectly afterwards, never the less I sold the car asap afterwards !
Paul.

 

[paultredgett]

...check your crank angle sensor out, the filings from the clutch stick to the magnet and when they are aligned in a certain way the car will start if the fly wheel/filings sits in an unfortunate negative position then the engine is a bitch to start or will only rev up so far before cutting out!
Usually a sign of the clutch breaking up!

 

[T BONE]

Thanks for the help guys it really is appreciated, I'm going to check out diesalman and panasonics solutions first because the problem also occurs while running on short trips so I think this would rule the crank sensor out??.
I'll let you know how i get on.

 

[T BONE]

Hi paul I just noticed you live local, can you recommend a good indie in rotherham or sheffield please.

 

[flango]

It will be the fuel pressure control valve or high pressure pump, we've replaced them before on ML's valve is the normal problem. Check out MAES on Hope street Rotherham they will diagnose it instantly and sort it out. We could have normally done it and are in Rotherham but unfortunately after our break in we are still lacking some equipment so it will be another couple of months before we can fully tackle everything again. Hope that helps.

 

[T BONE]

spot on guys it was the fuel pressure control valve.
I took flanaia1 advice and used MAES they diagnosed it instantly and replaced the part, £312 lighter but worry free driving again.
So a mega thanks to you all for your help, you are a credit to the site and all the members :bannana: