Diesel problems

[BenS]

Hi, my C220 N'96 is experienceing problems in cold weather once I have deaccelarated and accelarated again, it kind of mis-fires for a few seconds and blue smoke purs out of the back. I think that could be the air control valves, but im not sure, what could cause this, Do you know? Thanx in advance

Ben

 

[BenS]

no any ideas

 

[whitegold]

mine does exactly the same

I've been chasing air leaking into the fuel line from the tank to the injector lift pump, which has been causing some problems with starting and tickover.

However it seems that the hesitation & blue smoke is something else. I have been to an independent Diesel workshop and they diagnosed it by pulling off the vacuum pipes for the Air inlet regulator and EGR valves. With both of these disconnected, the fault doesn't occur.
They suggest this means that either the pressure sensor is u/s, or the control valve for the Air inlet, or both, or the ECU is faulty.

MB have also tested the ECU and step 1 in their proposed solution was a new pump...........

Let me know how you get on.
Regards& good luck

 

[whitegold]

final solution to occasional "Blue smoke"

turned out to be a pump rebuild. Not quite as expensive as an exchange pump, but just under £700, all-in.

Fault codes were: 1226 and 1230, that's "Cam position sensor". Offending sensor has been replaced, and now runs without blue smoke / EDC lamp.