Hey guys,


So ever since I bought this car, it has had what most would call a high idle (900 in D, 1200 in P or N)

I never sourced the problem, until last week. My brake booster vacuum line was severed , and to get the OEM part I had to order one straight from Germany.

Now, its idling at about 900 in Park or Neutral, and ~720 in D.

I am under the impression this is still about 150-200 RPMs too high.

There isn't another vacuum leak (Believe me, I have scoured that engine bay ) but I'm sure after a good tune up and adjustment, I should have her runnin' right.

So, is this high? And if so, what exactly should I adjust to get her back to 'normal'?

I'm also under the impression I'll need a new ICU and or Module, because I cleaned that ICU like no other.


Thanks,


Carlen

There are gaskets that seal the upper to lower intake plenum chambers together that fail over time. They are not fun to replace but after 20 years, they need to be done.

Not sure what spec is on the M117 for hot idle with load and without. I have a few vac leaks on mine.

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

Short of leaks. my first thought would be OVP. Is your ABS or battery light on? Secondly, the air idle valve needs cleaning or replaced.