There are waaay too many things that could cause a fast idle to immediately blame such an expensive part as the ECM.
Depending on your mechanical skills, you should get a manual & some tools and start shooting the trouble yourself, or go to a mechanic that knows these older type cars.
A lot depends on you and your particular situation.
If you want help, advice, suggestions, jokes, and good natured abuse, you've come to the right place. There are a lot of variables in the equation, so we will need some more info before anyone can start pointing you in the right direction, otherwise you get a "Karnak The Magnificent" type answer. Only not quite as useful.
Fill out your profile, give us the back story, and we'll try to help.
thanks for all the input. I am appreciating the help. This is the straight dope
Recently purchased the 280SL. Needs work and I knew that. First problem is finding a good repair manual. Tried books4cars.com but they sent me the wrong book.
1979 280SL, Model W107, Chassis 107.042, Engine 110.982/6 auto trans, We were told it was a 1979. You strike me as a bunch of guys who like numbers, so here's the VIN 10704212004812 I was told to put WDB in front of this to find parts. Took it to a dealer without great results - they were too busy and didn't have time to talk. Did give me a list of things to fix:
Said they tried to adjust mixtures for the idle problem - didn't work
I read on another site something about the ICM.
Aware of possible thermostat problem, but it seems to be heating correctly, but won't know for sure until I pop it out.
I now turn my questions over to my superiors :bowdown:
If you have the time, tools, and inclination, you will be rewarded with the immense satisfaction of being able to detect, diagnose, and repair a problem in such a manner as to save yourself a sizable chunk of money that would be otherwise spent at the dealership or possibly a questionable mechanic.
Before you can think of repairing it, try to find all the info on the net that relats to "CIS" or "K-Jetronic". Read all the explanations inclusive of those that are for other makes. There's plenty available specially for VW Golf (Rabbit) I.
Unless you generally understand how does this injection system operates in most of the conditions, advises you get here will be somewhat confusing in many cases.
I recon if a vacuum leak is to be blamed for 2000rpm, it would have to be audible, especially if throttling.
WHat about idle adjust screw, does it bring the rpm down AND does rpm go down* as engine warms up?
* down as in terms of slowing down a bit at least.
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