Hi,
My c200 w203 a few cold mornings there, struggled to start, but did on the second turn. It only happened twice on really cold mornings. During the rest of the days it was starting perfectly.

a few days ago i drove it to work. Everything was fine and i parked up. When i went to drive home, it would not start. It turned but wouldnt start. I got it towed to a mechanic who diagnosed it as the high pressure fuel pump issue. The pump was replaced and the pressure to the fuel rail is good now. but the car still wont start. It still tries to turn over but never starts. What else could be the issue?

 

Bad CPS?

 

Hi, thanks for the quick reply. The mechanic has tried spraying easystart and the engine does kind of start for a second or two but then dies again. Sorry i should have said that. Would that still be the crankshaft position sensor?

 

When you first switch on the ignition, the fuel pump is activated to initially pressurize the system. When you begin cranking, or even once the engine is running, if the ECU fails to get a signal from the CPS, it shuts down the fuel pump as a safety feature. So yes, it is possible that a bad CPS will prevent fuel delivery.

 

Hi,

The mechanic go back to me and confirmed that it wasnt the cps, he said the issue is the egr valve. He said he couldnt blank it as its not a normal valve that its embedded or something.

I know its possible to blank on other cars, is ot possible to do this on the merc also?

Of so, how do i go about it?

Chris

 

I've never seen an EGR valve prevent a car from starting. It can make it run rough or throw errors, but ti should still crank and start. Is this mechanic experienced with MBZ cars? I might look for a better shop.