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 > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 02-13-2010, 12:07 PM
Registered User
 
Join Date: Jan 2009
Location: Manchester,NH
Posts: 392
87 300SDL Rough idle issue

When the car is in drive it starts to idle a little rough. The same goes when you put it in reverse. When in park or neutral is runs smooth. Also when accelerating it runs fine, this only happens at idle. The quick fix has been to clean the wires that connect to the injection pump, and that fixes it for a day or two. Noticed that the hard metal fuel lines that deliver fuel to the injectors are wet on the pump end. Not too familiar with this but i have read something about some o rings that go bad and let air in. Not sure if that is what is happening, or if there are other issues

Reply With Quote
  #2  
Old 02-13-2010, 10:46 PM
Registered User
 
Join Date: Jan 2010
Location: Moncure, NC (near Raleigh)
Posts: 350
It could just be that when in Drive or reverse the idle is dropping to a point where it just shakes more. You could always turn up the idle a notch or two with the black knob in the engine compartment (drivers side near brake booster). Its a black dial about 1" diameter with the numbers 1-7 around it. I believe each notch will increase/decrease idle by 20rpm or so.

Definitely need to fix the fuel leak though. There are the 6 o-rings in the IP. Pretty easy to replace (DIY posted before). Use Viton if using Biodiesel

Let us know what fixes it once you find out.
__________________

1987 300TD 147,000 miles- Palomino leather interior, 1995 facelift and body cladding, E350 wheels, Rebuilt suspension and sport springs, rebuilt turbo, New Monarch injection pump and injectors....and the list goes on and on...
Reply With Quote
  #3  
Old 02-13-2010, 11:40 PM
Registered User
 
Join Date: Jan 2009
Location: Manchester,NH
Posts: 392
I will definatley replace the rings on the IP. I dont think its because the rpms drop. This happens randomly it will idle smooth and then rought, like its missing or not getting fuel for a second the smoothes out again. My guess is that it is sucking in air. I will try the seals on the IP and see if that helps. I am also thinking that the leak is getting the connection on the IP wet and causing a bad signal to the ip, because when I clean the connection on the IP it will be fine for a day or two.
Reply With Quote
  #4  
Old 02-14-2010, 05:48 AM
layback40's Avatar
Not Banned
 
Join Date: Nov 2009
Location: Victoria Australia - down under!!
Posts: 4,023
Roughness may be caused by weak left hand side (drivers) engine mount. The fuel leaks on the IP will contribute to this as the fuel softens the rubber in the mount.
__________________
Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving
Reply With Quote
  #5  
Old 02-15-2010, 01:26 PM
Registered User
 
Join Date: Jan 2009
Location: Manchester,NH
Posts: 392
can someone refer me to the DIY. I tried searching but cant find it.
Reply With Quote
  #6  
Old 02-15-2010, 08:40 PM
Registered User
 
Join Date: Nov 2004
Location: Nova Scotia, Canada.
Posts: 6,510
The phrase delivery valves should bring up ton of posts in the archives. Or delivery valve seals if it does not. They could easily cause this.

Fuel oil is not conductive to the best of my knowledge. For example large transformers can use oil as the heat transfer medium. It is a little strange that those connections seem to act up on the injection pump every few days.

Reply With Quote
Reply

Bookmarks


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 04:55 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