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 ShopForum > Technical Information and Support > Tech Help

LinkBack Thread Tools Display Modes
Old 10-29-2000, 08:14 PM
sixto's Avatar
smoke gets in your eyes
Join Date: Jun 2000
Location: SF Bay Area
Posts: 20,115
The M103 in my 91 300SE has developed an intemittent miss at idle/low rpm. Here are the symptoms:

-- takes a couple of seconds to stabilize on start-up. If cold, slowly rises to fast idle.

-- the miss feels like a cylinder or two skipping a cycle.

-- hasn't happened above 1500rpm.

-- has happened when cold, warm or hot. Basically anytime.

-- smooth as silk above 1500rpm. Will run with the best on the freeway.

I have the CD manual set but I haven't found a troubleshooting guide.

Any ideas will be appreciated.

Sixto Orosa
Santa Clara, CA
78 450SEL
91 300SE
Reply With Quote
Old 10-29-2000, 08:36 PM
Posts: n/a
I've found over time that low rpm missing is usually (but not always) related to a spark/iginition problem. Ends up being a plug worn to a very high gap, carboned up or fouled in some way, or a loose ignition wire/arced cap, cooked wires or something allowing the plug not to fire. Plugs are so cheap if I see this anymore I just change them and cure this most times. If it's fuel injected could be a dirty injector. The quick and easy high probability fix is:
1. New plugs (look closely at what comes out)
2. Can of Injector cleaner

Also, an easy check if you have an inductive pickup timimg lite is to keep it in the car, and when it does this, place the pickup on each plug wire in succession. If the wire (typically carries 15-30 KV) loses spark...the timing lite will blink (dark), quite noticeably. An easy way to troubleshoot the high tension side without taking anything apart.

I bet new plugs and/or a can of fuel injector cleaner solves it.


[This message has been edited by djenkins2 (edited 10-29-2000).]
Reply With Quote
Old 10-30-2000, 11:07 PM
Registered User
Join Date: May 1999
Location: Sacramento, CA
Posts: 1,472
As mentioned above, bad plug wires can cause a rough idle that goes away at higher rpms. A bit more involved (I believe you'll have to check resistivity of all the wires), but otherwise it's also a low-cost fix that worked for my 300E a couple years back.

Reply With Quote
Old 10-30-2000, 11:35 PM
Registered User
Join Date: Jul 1999
Location: Youngstown, OH
Posts: 150
read this site. You might want to turn off the groovy music and ove look the sometimes poor translations to english.
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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Intermittent miss in 1985 190E 2.3? Steve190E 2.3 Tech Help 5 08-06-2003 12:21 PM
adjustable intermittent wipers 95E320cab Tech Help 0 11-08-2002 08:43 AM
Cold miss/hot miss M117 MikeTangas Tech Help 14 02-28-2002 11:15 AM
'89 300TE (M103) Intermittent Stall burgeme Tech Help 4 11-08-2001 12:51 PM
450 door latch / engine miss intermittent Rkc Tech Help 1 07-17-2001 09:01 AM

All times are GMT -4. The time now is 04:35 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, 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