I've been searching the threads on this... TOO MUCH INFO!!! the car has a rough idle when the AC is off. instead of a steady prrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr... it sorta sounds like prr prr prr prr prr prrr.... the car has a slight shake kinda feeling like a sparkplug misfire..especially when the car is hot. but the sparks have been changed... twice in one year.. no help... I think wires have been changed... I know this is a fuel injected car and has no carbeurator to clean... are there any ignition coils that should be looked at that would cause such a problem?
What besides the OVP may cause this? Air Mass sensor /Oxygen sensor?, How could they diagnose that? What controls the Idle... I was reading somewhere that there was an Idle control valve that was controlled via vacuum lines? How could I check this? Does the 94C280 have this feature? What exactly should I look for? the people at the MB dealership have not been able to diagnose this problem for the past 3 years already. The only codes I have been getting have been for the EGR valve and that's been replaced. Can anyone shed some light? Please?

__________________
'94 MB C280 Lorinser Sport Suspension