Adjust idle ??????????
 

Hi,

I have a 1987 300 E and was wondering how do you adjust the idle? My car is reving at about a 100 rpm lower than it should in drive. How do i increase that to avoid the slight vibration/shaking that occurs due to this? Thank you.

I think you fix the problem rather than adjust around it, but otherwise I'm not sure of the steps to take.

what's the idle speed in neutral with the egnine warm? and when you first start in the morning?

there is a fix you can do to raise the idle speed by 50rpm but I'd be more inclined to look at your idle control and mixture settings first.

I would first unplug the electrical connection from the idle control valve. If idle speed does not change, then I would plug it back in in such a way as to be able to measure the voltage across the pins. If it is 0 volts, then your control module may be inoperative - check the OVP and the fuse(s) on top.

Steve

Thank you for the suggestions.

Friend,
Vibrations at idle are frequently caused by sagging engine mounts. There shoud exist a minimum of 13mm between subframe and the bell shaped shell of the mount.
dpk