My idel speed is a little low - 550 rpm how do I adjust it up ??

no provision for adjustment

Try cleaning the throttle & throttle butterfly.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Okay - how do I get the throtle body off the engine? I can barely see it with the air induction tube removed. Are there torix bolts holding on; how's the linkage connection disconnected; and where is the position sensor connector located?

Is this kind of stuff in the CD sold by Mercedes?

Clean the throttle on the car. remove the air intake plastic tube.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Hi CDB, did you follow M.B.DOC’s suggestion of cleaning the throttle & throttle butterfly? Any results? I did search and found this old thread but my car has same problem and I like to continue the discussion. I have ML320 (2002) with 55K miles. My car idles at 550rpm, a little low, but never stalls. The low idle speed cause the car a little shaking.

M.B.DOC: what liquid that I should use to clean the throttle? Is carburetor cleaning fluid OK? Should I just spray the cleaning liquid and let the fluid flow into the throttle body? Thanks very much for help.