M103 1500 rpm idle: icv?? - PeachParts Mercedes-Benz Forum

stormyc88 · #1 08-17-2012, 01:44 PM

Hey all,

I have experienced the very first running problem with my 87 300e this morning. Started up, idled great and cruised great on the 20-mile drive to work, like it always does. Stopped at dunkin donuts, and when I got back in and restarted it, the idle stayed at 1500 rpm. Run quality at that and all other speeds is just fine, as is throttle response. Would this be caused by the idle control motor? Any input would be greatly appreciated. Also, how hard of a job is it to change that? Big job?

Thanks!
-Chris

ps2cho · #2 08-17-2012, 02:21 PM

Two bolts hold it down. Pull it off and shoot carb cleaner through it to make sure there is no debris or dirt jamming it open.

Also inspect or replace the idle control hoses that are attached to it if they are rock hard.

i6h000 · #3 08-17-2012, 03:10 PM

Ck the WOT switch, small switch w/ roller activated by the throttle linkage. If you unplug it and idle returns to normal you've found your problem.

stormyc88 · #4 08-17-2012, 08:59 PM

Thanks for the input!

removed the icv and cleaned it, it was quite dirty inside.

checked the hoses and they feel fine, not hard or crumbly or anything.

Put everything back together and it idled normally, so..

is this it?? should I replace anything as preventative maintenance? or just leave it alone and see if it happens again and worry about it then?

ps2cho · #5 08-18-2012, 01:20 AM

You should do a normal standard tune up if you have no history of each individually.
Plugs, wires, rotor and cap and all fluids and filters. Other than that, leave everything as-is unless there is something wrong.

Adler · #6 08-20-2012, 03:19 AM

In addition to above new fuses will save many a intermittent problem.
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JamesDean · #7 08-20-2012, 02:10 PM

If the throttle microswitch is not being actuated while the linkage is in the idle position..the m103 will idle at 1500 rpm. just something to keep in mind.