Originally Posted by Douglas Matheson
Iím having the same idle issue and took it to an Independent MB mechanic (Budís Benz outside of Atlanta) who tested the idle control valve, tested the idle control box, tested air intake and all were functioning properly ... $400 later and no resolution.
Can you explain in more detail what you did to resolve your high idle as I am just learning and willing but not much experience doing my own repairs. Not sure what you mean by removing the pull tie or where it is located? Also, what do you use to clean the connections before plugging it back in?
I replaced the overload protection relay about a month ago and solved a hit idle situation, then I had the engine cleaned and as soon as I left the place, I was idling at 1500 RPMs in park and neutral ... about 900 RPMs when in gear.
I'm still dealing with it.
Could I encourage you to finish filling out your profile. Its helpful for us to know what year and particular model you have, as there are subtle differences over the 18 years Mercedes produced the 107s. Plus the forum moderators will start requesting you do this in the not too distant future anyway.
If you will look at the post that started this thread you will see a photo of what I meant by pull-tie.
You might have a wiring issue. Inspect your wiring. If your wiring has old cracked insulation you might have an open circuit. There is an online shop manual linked in the Encyclopaedia Germanica Volume 107 (aka EGv107) sticky link. I would check the fuses. Test the continuity of the wires going to the Idle Control Valve. Test to see if you have power at the power pins of the Idle Control Module. These are things that you can do yourself with a multimeter and an additional length of wire. Also you can pull the plug participial off the Idle Control Valve and test the voltage. At running temperature you should get 3 to 5 volts (I think). The ICV defaults to wide open. If it defaulted to closed your car wouldn't run, potentially leaving you stranded somewhere. I actually re-wired the top of my engine at about the same time I worked over my Idle Control System. My engine wiring was going to pieces quickly.
A common issue with these car at a certain age is the Idle Control Module goes inoperative. A company called ProgRama
rebuilds these modules. The cost is $130 to $140. (My car actually have the wrong model year module in her.)