Hello there-

The patient is an '86 560SEC. It had the dreaded "intermittent rough running and no power at all" problem for a few days now and it is getting worse. I checked and resoldered the terminals on the fuel pump relay, no help. I then did the same to the OVP relay. That is when I discovered a new thing. If I pull the OVP while the car is having the rough idle and no power situation it suddenly hits on all cylinders and idles at 1500rpm! Drives with full power as well.

Is is the OVP itself, or is it whatever the OVP controls that is the culprit here?? What does the OVP do? I hate just changing parts for nothing. Any help would be appreciated.

Thanks,

Alex