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 08-13-2002, 12:26 PM
Posts: n/a
Slow / rough idle 1987 300E

I recently purchased a one owner 1987 300E with 67,000 miles. My basic problem is a SLOW/ROUGH IDLE. The engine speed is approx 650 RPM. Above 1000 RPM it runs fine. Additional note is that it did passes the California smog test. (for whatever thatís worth) Unfortunately there is no idle adjustment screw or I wouldnít be addressing this forum.

Now for a list of what I have done so far with no change in the idle performance.

A plug check shows that the rear three cylinders appear lean and the front three cylinder are definitely rich. Spark plugs, cap, rotor and wires have been replaced. Both ignition timing and cam timing have been checked and are on spec. Interestingly the cylinder pressure is good at 150 psi, but the vacuum reading is low. I have replaced the fuel filter, fuel distributor, injectors and seals. The fuel pressure is 85-90 psi.

That's about it. Any suggestions would be appreciated. (just point me to the idle screw and Iíll be out of here!)


Last edited by rtarozzi; 08-13-2002 at 12:37 PM.
Reply With Quote
Old 08-13-2002, 02:29 PM
haasman's Avatar
Registered User
Join Date: Jun 2001
Location: San Francisco, CA
Posts: 3,096

Welcome to the site! Use the search button. There is a ton of listings under idle problems etc.

Of course my favorite is the super tonic remedy: Add two bottles of Techron and drive it. It could be your injectors are just plain dirty. Start with this and see how it goes.

I just did this on a newly acquired 190E 2.3 that ran very poorly. Check this out:

190e STalls when put in gear

'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)
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 08:30 PM.

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