i have an 86 420 sel. it idles at 1300-1500 rpm in idle and at approx. 700-900 rpm in drive at a stop depending on engine temp. also idle soars to about 1800 rpm on startup at any engine temp. any thoughts? according to mb service manual the only thing that causes a high idle is a coolant temp. sensor and it has been checked.
ifyou have any suggestions i would greatly appreiciate. it is my only car right now and i really need to get this rectified before i blow it up. thanks so much