Hello.

I have a problem with my 300E. Cat and lamnda, no EGR.

The engine is sometimes idling to high, 1050-1500 rpm in "N" or "P" and little lower in "D". The idle is often slowly increased from the lower rang to the upper range...

I have tried to disconnect the idle control valve, and then normal idle is achived.
Also if I connect the mass airflow sesor plate potentiometer the idle comes down to normal after a few seconds.
When I tried to disconnect the throttle switch the idle went up even higher and did not come down after reconnecting it...

So to my question(s) ;-)
I did a forum search and found a few probable causes for this problem, however nobody stated that disconnecting the airflow sesor plate potentiometer would give normal idle, however there was talk about worn potentiometer could cause high idling... Nevertheless, someone stated that this potentiometer would have no function at all in closed loop cycle... I'm confused ;-)

Still I'm suspecting this potentiometer to be the problem... How can i check it?!?
Also Is there a problem with driving without this potentiometer connected?

Seccondly, this problem started after I changed my fel filter (which by the way somewhat solved my cold start problems)

Thanks!
/Ola, Sweden