Once in a great while (and very randomly), my 1993 190 2.6 (77k miles) will idle high. Usually it occurs when I hop errands and am re-starting the car, where the idle will run up to 2200rpm and stay there until I punch the go pedal a little and it will settle back to 750 or so (normal). Today, I got my car washed, drove it the remaining 1/2 mile to work and when I arrived and put it in park, the idle raced up to 1700-or-so rpm. A few jabs at the gas never brought it below 1200 and it stayed at 2100-2200 without falling (or re-setting itself). What gives?

If it is anything like mine was, it is the Idle Speed Control module.

Q:

Can you elaborate a bit? Do you have a 90's 190. Or other with the 2.6? Was is the SAME symptoms or similar? Was it a reprogram of the control or replacement?

I have a 126 model with the 116 engine, so I don't know if they are even related at all in design. I do know that you described my symptoms to the letter and that was what was wrong with my car. It is a little black box that holds a circuit board. Solder joints sometimes break on that board, or a part burns out and causes it to fail. I have found remanufactured boards for $90. You first need to find out if that is definetly it, and on this car, I am the wrong guy to talk to. Sorry if I detracted from your solution.

Matt:

Sounds like it's time to call our buddy Al over at ******** Los Gatos. You can also e-mail him, he usually replies (or calls me) by the next day.

Brian

Be sure that they check the basics, sounds like a throttle switch to me.

------------------
Benzmac:
Donnie Drummonds
300E
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

Sticky/frayed throttle cable? Could be worth spraying some penetrating oil into it, and lightly greasing the throttle actuator.