W126 Racing Idle

[Rodney380]

Hello again All,

I have had an account here before, and have recieved some great help from Phil before...it seems my account must have expired.

So, I have an '82 380SEL with an odd idle issue. The car will sometimes rev to 2000+ idle speed, but at other times idle perfectly normal. It may race for a week, or a day, or an hour. It may idle normally for the same amount of (completely random) time.

I have guessed, after reading through the forums, that it may be the idle control system ECU. I would guess the problem is much more likely to be electronics rather than vacuum, given the randomeness of it's occurance.

If it is the ECU, where on the car would I locate the box? I think under the dash...but where?

Thanks for the advice/help!

[pantherpaw]

my 300ce was doing the same thing, it turned out to be the linkage bowden cable was not screwed into the right position, which wouldn't let the linkage press on the micro switch (the switch that makes the car know that the engine should in idle)...dont know if your model even has this cable and switch, but its worth looking into.