Hi,

I recently solved an intermittent stalling problem on my son's 190E by replacing the Overload Protection Relay (Over a week no stalling). I have a new problem with a very rough idle.

Last week after replacing the Overload Protection Relay I decided to flush the antifreeze and replace the instrument cluster to hopefully get the speedometer working. After changing the instrument cluster with one purchased on ebay. The speedometer was still not working so I realized it was probably the cable which I ordered and will replace soon. When he was driving back to school he called to say the car was idling like my 300D but was not stalling. I thought he was exaggerating and went to check yesterday. He was right the car shakes like it was running on 3 cylinders. I
swapped cars and drove his home to work on it (180 mile trip). The car ran fine at highway speed but as soon as I stopped it shook like the diesel.

I removed the plugs and they appeared fine. Next I removed the wire from the closest plug to the front of the car and there was no difference in the rough idle. Removing the remaining wires one at a time made the car stall.

Does anyone see a link between the work I did that could have caused the problem?


What should I check from here?

Could it be a vacuum hose that is causing the problem?

Any troubleshooting advise would be greatly appreciated.