[Fredws]

Hey guys, I have a 1991 300E 2.6l that is having an issue when you let it idle for a while, like five minutes or so. It will start idling rough and missing, like it is loading up. If you get it on the road and blow it out for a couple blocks, it runs great again. It only does this if you idle it for a while, runs just fine if you are just at a light for a bit or so.
I just put on a new distributor cap, rotor, dust shield, all Bosch. I didn't do the wires because they look new, and seem to pass the "inspect in the dark" test. Also has new spark plugs. I have also checked and adjusted the fuel pressure. New OVP relay for good measure.
Not really sure where else to look at this point.
TIA!

 

[sbaert]

What about the suppressor disc and O ring at the back of the distributor? Ditto on the metal T shaped rotor arm driver. The design was updated.

 

[Fredws]

I did replace the suppressor disc and o ring, actually it didn't even have one in there, so I thought I had found my problem, but nope.
I did not replace the T shaped driver, do you think that would cause the issue?
Thanks!

 

[Fredws]

Okay, I have finally gotten a chance to revisit this issue. I read the error codes, of which it had several, which I cleared all of them, took it for a drive, and I am now getting error code 25 Short circuit to positive in Start Valve circuit

Am I understanding this correctly, and it is running the cold start valve when it is not supposed to? If this is the case, it would certainly explain the apparent loading up when idling for extended periods. Where should I look to find the problem, assuming my thinking is not flawed here?