Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help

Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Tech Help

LinkBack Thread Tools Display Modes
Old 12-29-2002, 03:28 PM
Registered User
Join Date: May 1999
Location: Sacramento, CA
Posts: 1,565
idle/decel microswitch

What does this part actually do? I was cleaning up my accelerator linkage a couple of days ago, and noticed that the arm on the microswitch actually rides up on top of the linkage arm and doesn't actually "click" the switch. I tried bending the arm down, but there's too much play in the joint, and it doesn't stay in contact with the side of the linkage.


1987 300E 238k mi

Reply With Quote
Old 12-29-2002, 03:41 PM
Registered User
Join Date: Oct 2002
Location: Toronto, Canada
Posts: 700
the switch shuts off fuel flow, very good for economy, my car had the same problem, the fulcrum lever didn't reach it and it only got engaged every now and then until I replaced the spring on the lever, now it's fine.

Reply With Quote
Old 12-30-2002, 05:38 AM
Registered User
Join Date: May 1999
Location: Sacramento, CA
Posts: 1,565
Thanks for replying. Do you know how it affects the idle control? My fuel economy isn't bad (about 24 highway, 20-21 with a 50/50 driving mix), but I do have a bit of an idle "burble" that you can feel through the chassis. (Also, rpm's will occasionally be unstable.)

Reply With Quote
Old 12-30-2002, 09:10 AM
Join Date: Mar 2000
Location: Gainesville FL
Posts: 6,844
Good question, here is hoping for a definative answer as I don't know. The switch obviously affects decel cut-off by indentifying closed throttle, but there already was a closed throttle switch in earlier 103 KE systems and it continues after the introduction of the decel idle switch in about 88.

I can tell you it does affect idle. Its my impression that it (along with the regular throttle switch) participates in the off idle control state. This is the strategy the valve takes when the speed is "high" but the throttle is open. Normally the valve would close at "high " speed but this is not what you want to happen when idle is not the point.
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician
Reply With Quote
Old 12-31-2002, 05:09 PM
Registered User
Join Date: May 1999
Location: Sacramento, CA
Posts: 1,565
Alright, in that case I think I have my switches mixed up. I must be looking at the closed throttle switch in my '87.

In the case of the decel switch, it sounds like it allows the control unit to distinguish between the idle state and deceleration state (hence the name of the switch) when there is no accelerator input in both cases.

Thanks for replying. In my case this is more a question of curiosity than actual diagnosis.


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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 07:39 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page