High idle on my M103 - PeachParts Mercedes-Benz Forum

mia · #1 07-26-2011, 08:17 PM

idles about 1k don't know how to lower it? cant find anything on the search

ps2cho · #2 07-26-2011, 08:31 PM

Try this:

Quote:

Idle Control Valve

1. Check switch-off point of additional air valve. With coolant temperature below 70°F (20°C), engine should idle at 900-1200 RPM. Idle RPM should drop to normal when operating temperature reaches 160°F (70°C).
2. If cold start idle is too low, compress connecting hose between idle speed air distributor and additional air valve. If no RPM change occurs, additional air valve is seized and must be replaced.
3. If idle RPM is too high at operating temperature, pinch connecting hose between idle speed air distributor and auxiliary air valve. If idle speed changes, auxiliary air valve is sticking or is not electrically heated.
4. Check voltage and resistance of auxiliary air valve. Nominal voltage should be 12 volts and nominal resistance should be 40 ohms.

mia · #3 07-26-2011, 08:34 PM

any pics of the connecting hose between idle speed air distributor and auxiliary air valve?

ps2cho · #4 07-26-2011, 10:51 PM

There are two hoses, both rubber. One goes under the fuel distributor, the other under the intake manifold. Can't miss em

I would take the opportunity regardless and remove the ICV, shoot it with carb cleaner completely (I bet ya you'll be surprised how brown the fluid will come out) then replace BOTH hoses. If you haven't done them yourself, its time. Follow this guide for the most difficult (intake side) this trick will save you a lot of time:
http://www.w124-zone.com/articles.php?article_id=35