300E stumbling idle upon startup, then OK
 

88' 300E - 154,600 mi, clean, perfect - except that when engine is hot or cold, in warm or cold weather, almost every time the car is started, car starts immediately upon cranking, then stumbles - feels and sounds like you can count the detonations for about 3-6 seconds, then resumes normal idle - otherwise, perfect engine operation, power, response and gas mileage - no missing or hesitation - comments as to possible causes and how to repair will be appreciated

Could be the overvoltage protection relay. Its a quick and easy job even for someone with no experince. It should be located along the firewall, a little silver box with a clear plastic cover and a red 10amp fuse in it. Check the fuse first. If it is good you may need the OVP relay. Mine cost $65 with tax (Canadian dollars) they just pull out and plug in. Many people on this forum have had problems similar to yours and fixed it with a new OVP. On the other hand a number of things could cause this problem, and there is no guarantee that the OVP is your problem.

STUMBLE IDLE
 

To 420 SEL:

Thanks for response - please enlighten me as to how the overvoltage protection relay may be the cause of my problem - my "mechanic" friends did not connect the trouble with any electrical functions - thanks in advance

When you start the car, leave the key in the on position for a couple of seconds before engaging the starter. If that helps any, you might have a bad accumulator or fuel pump check valve(s).

Sixto
91 300SE
81 300SD

I also experience a stumbling in my 300te. Only mine is more sporadic. Would you guys say to look for the same thing?

Thanks, Ranger

Ranger, yes.

Barbershoptenor, if your friends are not familiar with Bosch KE-Jetronic, they'll have no idea what an OVP relay is. Ask how many of them would expect your engine to keep running if you disconnected the ECU? I'll bet they're not familiar with your car's limp home feature.

Sixto
91 300SE
81 300SD