w211 om648 rough idle misfire

[gilighan]

My 2003 E320cdi 204hp time to time heavy misfire on ocassion when fully warmed up.
under way to be warmed time to time light misfire.Egr is cleaned,no fault codes,injector replaced.Leak off test all of them with same quantity.No problem with fuel consumption.No problem with acceleration.
When the car is idling the fuel pressure fluctuates between 316 and 336 bar.
Pressure control valve position is reported between 27.4 and 28.8% - I presume this is Y74 on the fuel rail.
Y94 Quantity Control valve between 41.9 and 43.9%.
Injected quantity of fuel between approx 6.6 and 8.8mm^3/Hub also variable RPM 640-750.
When engine work smooth RPM 680 and fuel quantity 7.5
When engine work rough idle injection corection on all the injector pass 5,but no smoke behind.Only engine jumping.

 

[mercuxio]

Hi,

Did you ever find the problem? My e270 has the exact same problem.

 

[gilighan]

Dear friends,problem is very special!!!I fixed.The proglem was in engine ECU.Cannot make injector corection.On high RPM no problem,you can run 1000km without any problems.But when you stop ECU cannot fix injector corection and engine run rough.Its replaced with another one and everything is ok.Sorry for my english,friends.This is very important post.Benz Ecu is not so strong!!!

 

[mattkh]

........Benz Ecu is not so strong!!!

MBenz ECU lasted 19 years.
And only injector number 5 was affected.
I think on the diesel engine the vibration can be a cause.