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 02-26-2018, 11:52 AM
Registered User
 
Join Date: Jan 2018
Posts: 33
300CE M104 CIS (1992) hot running woes

OK I have two of these frustrating cars, both with similar problems.

The '92 (with 95K MI) starts readily when cold, with maybe a little off idle stumble for a sec, then runs well at all RPMs and throttle positions while still cool, and much of the time when normally warm. In fact, the engine seems super smooth and strong when it is running right.

Sometimes, though, it gets to running very rough when warm. It has stranded me twice by shutting off then not starting back up. Now I am reluctant to drive it anywhere.

When this happens (its not every drive), the poor running gets progressively worse over about a 5 min period, it is not all of a sudden. Seems like 1 or 2 cylinders start skipping first. Also, it seems that if you can get above idle/low throttle input/low RPMs into high throttle/RPMs, the problem clears while operating there. Tough to do at a stop light, putting in neutral and revving is not enough. Once, it about died on me, but luckily I was able to get to an open road, and then the issue(s) cleared after some driving?

If it matters, the tachometer operation seems normal during the fits. On my 944T, the tach quits when the DME relay is acting up.

Sure would appreciate a checklist.

Reply With Quote
  #2  
Old 02-26-2018, 12:28 PM
tyl604's Avatar
Registered User
 
Join Date: Feb 2008
Location: Atlanta, GA
Posts: 3,640
Fuel filter?
Reply With Quote
  #3  
Old 02-26-2018, 01:11 PM
Registered User
 
Join Date: Jan 2018
Posts: 33
Thanks, pretty sure the filter was replaced a few months ago. The car seems to run fine when higher fuel flows are needed.

Of course, there could be junk in the tank that could have the new one plugged up.
Reply With Quote
  #4  
Old 02-26-2018, 02:10 PM
Registered User
 
Join Date: Feb 2011
Location: Modesto CA
Posts: 4,078
rb:

If you can eliminate ignition, consider that the fuel pump relay may be opening intermittently, or that one of the fuel pumps (two, in series) occasionally slows or stops due to worn brushes.
Reply With Quote
  #5  
Old 02-27-2018, 08:58 AM
Registered User
 
Join Date: Jan 2018
Posts: 33
Update, got brave and drove the car yesterday for about 1/2 hour. No problem with a restart following about a 12 min drive. At the next stop, I let it idle longer than intended, maybe 10 min, temp went up to higher than normal moving along temp, still no problem.

Just as I parked it at my destination after some more idle time, it was beginning to stumble off of idle, and goosing the gas pedal did not clear the stumble. I'm pretty sure it would have fizzled out in another 10 min.

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




All times are GMT -4. The time now is 05:38 PM.


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