Parts Catalog Accessories Catalog Tech Info Tech Forums
  Search our site:    
 Cart  | Project List | Order Status | Help    

Go Back   PeachParts Mercedes ShopForum > Technical Information and Support > Tech Help

LinkBack Thread Tools Display Modes
Old 06-24-2002, 06:19 PM
pmizell's Avatar
Benz Zealot
Join Date: Jun 2001
Location: Houston, Texas
Posts: 838
Decel-shutoff/idle microswitch

I've been having high idle problems lately (1000 and above at times) and I'm pretty sure it's related to the idle microswitch that comes in contact with the throttle linkage.

When idling high, I'll depress the little roller and idle returns to normal. (750rpms in neutral; 500 or so in drive)

I've tried adjusting the throttle cable via the adjusting screw so that the linkage depresses the microswitch roller further in, but no luck. Pic attached shows the microswitch in the idle position -- does this look normal or should the roller be closer to the switch itself?

Here's a blurb from another post I dug up:

I had a similar promlem with unstable idle on my 300CE and the problem was the idle microswitch.
Make sure all the linkage and the switch are clean , mine was covered in oily dirt , then check that the microswitch clicks every time the gas pedal is up.
You may need to bend the switch arm very slightly to make it work every time
I can't quite decipher what the poster means when he says to make sure the microswitch "clicks" every time the gas pedal is up. The quote is courtesy of Larry Smith.

Any insight/advice/thoughts is appreciated as always


'91 300E, 213K miles
Reply With Quote
Old 06-24-2002, 06:42 PM
Amuso's Avatar
Addicted to gadgets
Join Date: Apr 2002
Location: Norway
Posts: 102
I think he meant that you should listen and see if you can hear it click when you release the gas pedal. Microswitches usually makes a little click when you activate them.
99 W210 E220 cdi sedan automatic (248.000 km) 210.006
Reply With Quote
Old 06-25-2002, 12:28 AM
Mike Murrell's Avatar
Registered User
Join Date: Feb 2000
Posts: 2,141

Not to criticize, but things look a little dirty...linkage, etc. Id' spray that area with some carb cleaner, then apply tranny fluid to the linkage. Give it a bit and see if things clear up.
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC

James Madison - Oppressors can tyrannize only when they achieve a standing army, an enslaved press, and a disarmed populace.

Liberty Firearms Training - After years of trying to regulate California criminals with a never ending stream of gun control laws they have still not given up with the belief that if they make something a crime that criminals will miraculously start obeying the law.
Reply With Quote
Old 06-25-2002, 10:46 AM
pmizell's Avatar
Benz Zealot
Join Date: Jun 2001
Location: Houston, Texas
Posts: 838
Thanks Mike...

I agree. Maybe some degreasing will do the trick.



'91 300E, 213K miles
Reply With Quote
Old 06-25-2002, 04:22 PM
csnow's Avatar
Registered User
Join Date: May 2002
Location: Mass
Posts: 1,127
Had the same problem.
I found that the wheel/switch itself was not actually the problem. Other parts of the linkage were sticking, and not allowing the springs to return it to idle state.

I went wild and dissassembled every ball joint for a 'clean and lube', then cleaned and lubed every other moving part on the linkage. I also cleaned and lubed the little wheel, which was not rolling. I used lithium grease throughout.

What a difference! When I first got the car, I thought the accelerator was designed for big Germans with strong legs, then I realized it was simply all gunked up.
1986 300E 5-Speed 240k mi.
Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 03:06 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page