I agree check the female pins for tension on a male terminals.
I had one a week ago the only way the vehicle would stay running is holding the relay to one side promoting a good contact I found eight pins loose on two relays. Tim

I agree too..
There was one here last week that drove the guy nuts, but we found it by back probing w/ohm meter.
The problem with OVP install is guys think that they plug into a solid, chassis mounted socket,.... when, in fact, the connector plug on the bottom is just a loose harness and has to be held while the OVP is pushed into the plug/sockets to make a positive/seated connection..It is hard to see down there , so make sure one uses both hands to assure the OVP is seated ..battery out of the way and hood to full position helps on some models.

Hi Guys,

I just heard back from my mechanic and he cautiously says Bingo! He tightened the connections on the OVP and the car has been idling normally for about a half our.

Thanks for your expert advise. I will keep you posted.

I Can Provide Only Moral Support
 

Quote:

Originally Posted by davestx (Post 1550054) ... The symptoms were that the car would start and then idle erratically with the rpms going from 750 to 1700 over and over and then stall.

I had this exact same problem in an '88 420SEL!!! Took mine to the dealer (Claridge's Mercedes, now Fletcher Jones in Fremont, CA) and they worked on the problem for a little over 3 weeks. In the end, they charged me for a computer and 2 hours labor. However, I'm not so sure that was the real problem.

My only reason for adding this post is:
A) I'm real interested in seeing what the fix is and,
B) Lend moral support to davestx

It can be real scary watching the tach jump spontaneously above 1500 RPM with your foot off the peddle. Thank God I didn’t hit anything when it happened while driving.

Guys I think that was it. Now she purrs like a kitten!
Thanks for all of your help. Now for the trans flare.......:)