To rick 76, the part # is 004 545 11 32 another number on the box is 412.214/001/002
To dhjenkins, i'm not sure what you meanby a KOEO, i do have a volt/ohm meter, and the idle control solenoid has 2 wires, and the control module has many pins, so i'm not sure which pin corresponds to which wire on the idle solenoid. While I was out, i went to CC German motors, where I know the owner/mechanic, he told me that the idle control module regularly goes out on my '87 560sl. He is going to see if he has a used one, but they were closed when i called a few minutes ago, and i'll have to wait untill monday to call back. Also, the module with the broken contacts is for the climat control, but i was able to re-solder the broken connections-at least i was able to fix that! i hope he has a used module, ifnot i sure can't afford the dealer, so the car will have to just beparked. in the mean time i have all weekend to troubleshoot, any more suggestions?

thanks,
ddayme

i don't know if the last message i typed maed it in or not so here it is again: forRick76, th part# is: 004 545 11 32 another number on the module is: 421.214/001/002
For dhjenkins reply, i'm not sure what a KOEO is, maybe a volt/ohm meter? the idle solenoid has 2 wires, and of course the module has 11 pins, so i'm not sure what pin corresponds to which wire on the idle solenoid. i have a friend who owns CC German motors looking for a used idle control module, he says these modules go out all the time on the 560sl's. i guess he went home early when i called back a little while ago no one answered. i will haveto wait untill monday to find out so i have all weekend to trouble shoot! if i can't figure it out, and he doesn't have a used module, the car will just have to
be parked!!....that would really suck! so any more help on this problem is GREATLY appreciated!!

thanks,

ddayme

Sorry, I got my acronyms wrong. KOEO means Key On Engine Off, but I meant Key Off Engine Off.

Should be pins 6 & 7, a black and black/yellow wire.

Thanks, I'll try that. Took off the IACV,it was surprisingly clean, theaction was smooth and all, vaccum lines all looked okay, i replaced a suspect one, and went over all the solder joints on the idle speed control module. Now if it still does the idle thing, I will trace the wiresfor a break or sonething. I also read the link titled "high idle hell"- very infformative, I hope my problem is just bad connections/solder joints. Will get back with my results!

Thanks for all the help so far.

Well, I just cranked it up, and NO MORE HIGH IDLE! it seems that whatever I did solved the problem, but I didn't do anything tha you guys did not suggest! I will post a reply with the final results, after I make certain it is fixed, a feat I could not have accomplished without all you help. This will enable me to continue using this fine automobile, which is the only thing I was able to retrieve from my father's estate (a long, not very pleasant story). Again, thank you all so much for the tips/suggestions, without which I would have been at the mercy of the dealer-not that they aren't great people, I just don't feel the need to contribute to their wealth, as I "ain't got no money"
to give.

Again, many thanks, I will postfinal results.

God bless,

Dwight Daymen (user I.D.-ddayme)

560sl high idle resolved!
 

Well, after 90 or so miles of driving, my high idle issue still seems to be fixed, so here'e what I did: remove and cleaned idle control solenoid, removed and re-soldered all solder connections on the overvoltage protection relay, remove and resoldered all connections on the idle speed control module, cleaned all pins on sensors under the hood, checked all vaccum lines I could see, and used some high temp silicone on the rubber hose that he idle speed solenoid wac connected to. As far as the re-soldering, I used an otoscope I bought from a garage sale (ear doctor??), so I could look a the solder joints REALLY up close, boy that will strain your eyes! on the idle speed control module, 2 of the pins had real suspect looking solder joints on the component side of the board.

Once again, I couldn't have done any of this without the excellent help/suggestions I recieved on this site!
Thank you all again,
-ddayme

my 86 560SEL just started idling fast about 1200 RPM. fuel economy meter pegged to the left. i pulled the connector off the idle control air valve while engine running and the idle increased significantly

so ... does that mean air valve is OK or could there be issues with it.

a few days ago i sprayed the engine down with some water and degreaser just to clean it up a little. did i mess something up???

If you pull the connector off the air valve, and the idle jumps up, you valve and control are probably functioning.

With the engine running, spray gumout carb cleaner all around the air hoses on both side along the valve covers, and under the plenum where the cross hose goes. If idle changes while doing so, you probably have a leak in one of the air distribution hoses or one of the vacuum hoses.

All new air distribution hoses will cost you about 125 and an hour of work. Hopefully, you simply knocked a vacuum hoses off somewhere.

Good Job. You will probably find that lots of problems on W126 cars are caused by bad solder joints. I have seen them in just about every system.