I have a 1988 300E, with 100K miles. The car starts fine and is fine at highway speeds but has a very rough idle, the RPMs range from about 5-800, and the needle fluxuates slightly. The vehicle shakes as well at idle. When I step on the gas pedal, there is a lack of reponsiveness. Usually, I will step on the gas and it acts like it will stall and then the engine catches up to the gas pedal and accelerates as it normally would. It stalled once at a stop sign. Any ideas on what may be wrong? Thank you.

 

thers a relay behind the battery with a fuse on top im told its the ovp relay my 1990 300e had the same problem the garage changed it and it stoped stalling there between 55-75 dollars depends were you buy it its about two or three inches tall .