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

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 04-12-2000, 10:50 AM
Stan
Guest
 
Posts: n/a
This only happens in the mornings after the car has been sitting overnight-- after startup and driving for about 2 miles, the engine seems to slightly surge as if a couple of injectors had not been working and they finally kick in. The injectors, plugs, wires, distributor cap, rotor, and fuel filter were all replaced 6 months ago. The car doesn't miss at all when driving - only a slight miss at idle. Any thoughts on this surge after about 5 minutes of driving? Cold start valve?

Reply With Quote
  #2  
Old 04-12-2000, 02:50 PM
Moderator
 
Join Date: Mar 2000
Location: Gainesville FL
Posts: 6,844
Lots of things cause surges, but surges also mean different things to different people. I associate the word surge with performance problems that cause smooth changes in power. The other word used is misfire. Misfire is a single or multiple cylinder drop in power that I associate with vibration.

Surges usually are fuel or timing related - things that affect everything but not bad enough to cause misfires. Single cylonder misfires are usually caused by plus, plug wire resistors or single injectors. Vacuum leaks can cause single cylinder leaks at idle that go away as things move faster.

One common idle misfire on both 420s and 560s is the vacuum line that goes to the transmission modulator. The line attaches to the lower manifold at the back of the motor right above the "HOT" crossover pipe for exhaust. The heat does in the small rubber connector.

The reason I mention this is that I key off the fact that you say it doesn't happen cold. The main difference cold that helps cars run is mixture. Everything else works against cold running. Ignition should have a worse time cold. But the car will be running rich enough on cold enrichment to get by a small single cylinder or two misfire.

If none of this help, describe the conditions the problem exists. Engine speed? Engine temp? Throttle position? A/C 0n/off? Any other repetative characteristics? How do you feel the problem?

------------------
Steve Brotherton
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician

Reply With Quote
Reply

Bookmarks

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
Possessed Becker 1480 in 1990 420SEL benzboy87 Car Audio and Multimedia 0 11-10-2004 08:12 PM
1990 300E or 1991 420SEL argyleco Featured Cars 1 03-31-2004 09:45 PM
1990 420SEL a/c compressor change pr'ot hed Tech Help 2 08-27-2003 07:09 PM
Selling My 1990 420SEL in MD. Hunter Tech Help 1 07-04-2001 01:50 PM
190E vs. 420SEL TimBru99 Tech Help 5 10-13-1999 09:09 AM



All times are GMT -4. The time now is 03:27 AM.


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