Pulsating Idle
 

I have a 92 300 CE and after I start it up the idle pulsates up and down both in park and when in gear at a stop sign. I have read may posts on ICV and other cuases. Any help will be appreciated.

If you have a throttle body the wires inside rot,and touch each other.Rewire it.

I would start by reading the fault codes, especially pins 3 and 8.

May be due to a faulty airflow meter. If the pot on the side of the airflow meter is sending a incorrect reading then the idle valve is going to try and compensate for the new value its reading. Use a ohm tester to test and see if there are any fluctuations around the idle range while pushing up and down on the plunger slightly. If the value doesn't imcrease linearly with the pressing of the plate then the air flow meter is probably the problem.

BENZ TECH

I also live in Chesapeake, VA. Where are you a tech at? I need a good indy.

Nick

Best to clarify if the engine is M104.981 or the later one with HFM system.

I would suspect a vacuum leak somewhere.

Whatever, START CHEAP. Don't assume that something expensive is trashed.

RayH