CIS-E Idling Problem
 

I have an '87 190E 16V with a hunting idle issue. 235K on it. Well maintained, I've owned it since '96. Parts replaced so far, O2 Sensor, Idle Speed Air Valve, EHA, Pumps, Shut Off Micro Switch, Pump Relay, CIS-E Control Unit. I found the fuel pressure problem myself, and replaced the pumps. I've had 3 shops all stumped replace the other parts telling me they we're probably the issue. I have also cleaned the plunger in the fuel distributor. If I "drive down" thru the gears I can get my warm idle to about 1,000. Driving normally it will sometimes idle aroung 1,000, and sometime slowly climb to 1,800-2,200. Sometimes it will hunt anywhere from 600 to 2,500. It's driving me crazy, any ideas? :dizzy2:

Hi repapyob,

how do you clean the plunger of the fuel distributor? Do you need to detach it, get it free from the injectors?

Thanks!

Might be worth a try to test the coolant temp sensor with a multimeter. Don't have the exact values you need, a search should bring em up.

Always found it odd how shops rarely get the multimeter out to test components. They just want to slap on a new part and cross their fingers.