Hi Guys

Did you fix your idle problem?

I have a similar problem:

1994 c280

Starts fine, idles fine when cold - When reving the engine the revs slow drop to 1000 then slowly back to about 600 and stabalise.

Engine starts to warm,few mins and starts to run rough at idle speed, revs freely and runs well if driven, no sign of stalling until speed drops to almost nothing or stopped.

When in this warming stage if the engine is reved at stop, the revs drop straight down to 0 after taking the foot off the accelerator. They do not slow ffrom 1000 down to 600 just drop straight off.

When warm the engine idles and runs fine about 80 degrees.

Check OVP relay number against SB and its the replacement item. Can it be checked and could it be this?

Is there an Idle valve?

Kind Regards
Si