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

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 06-29-2003, 02:25 AM
EricSilver's Avatar
Registered User
 
Join Date: Mar 2000
Location: Fairfax, VA
Posts: 1,216
Will Leaky Injector Seals cause Rough Idle?

1989 260E

I have 3 or 4 leaky fuel injector seals that I plan to replace this week. Could they be contributing to somewhat rough idle -- with the car continuously trying to adjust fuel/air mixture?

I have an all-new and Position Sender Unit, distributor cap and rotor, STI spark plug wire set and properly-gapped Bosch copper plugs. Fuel pump relay, OVP and ignition control unit are all fine.

I have always had a slight rumble at 500-600 RPM idle, which goes glass smooth at 1000+ RPM (at which point I can't tell if I even have an engine). My assumptions are the leaky injector seals, or perhaps a dirty fuel filter (which I also plan to replace this week).

Any thoughts?
__________________
2001 E430 4matic
122,xxx miles
Black/Charcoal Interior

------------------------------------
Gone but not Forgotten:
1995 E320, 252,xxx miles, Black/Grey
1989 260E, 223,00 miles, Black/Black
Reply With Quote
  #2  
Old 06-29-2003, 10:07 AM
Registered User
 
Join Date: Jul 2001
Location: SoCal
Posts: 1,303
"I have 3 or 4 leaky fuel injector seals that I plan to replace this week. Could they be contributing to somewhat rough idle -- with the car continuously trying to adjust fuel/air mixture?"

Sounds plausible, but how do you know they are leaky?

Steve
__________________
'91 MB 190E 2.3
'08 RAV4 Ltd 3.5
'83 Lazy Daze m'home 5.7
Reply With Quote
  #3  
Old 06-29-2003, 10:23 AM
EricSilver's Avatar
Registered User
 
Join Date: Mar 2000
Location: Fairfax, VA
Posts: 1,216
Hi Steve,

My mechanic told me, and showed me, by spraying carb cleaner (??) around the leaky injectors, and pointing out the higher CO2/NO readings on an emissions test machine after the cleaner fluid burned.

Since the electrics (plugs, wires, distributor, sender unit) are all new, the OVP, FPR and coil are almost new, and the ICU is in good shape, it seems to boil down to a fuel/air mixture problem.

The leaky injectors have skewed emmissions tests and the car intermittently pumps too much and too little fuel which seems to me could also impact idle smoothness.
__________________
2001 E430 4matic
122,xxx miles
Black/Charcoal Interior

------------------------------------
Gone but not Forgotten:
1995 E320, 252,xxx miles, Black/Grey
1989 260E, 223,00 miles, Black/Black
Reply With Quote
  #4  
Old 06-29-2003, 11:04 AM
Registered User
 
Join Date: Jul 2001
Location: SoCal
Posts: 1,303
Sounds like a solid test. I recently inspected my injectors, when I received what were SUPPOSED to be the new injector seals. I wanted to make certain that if I damaged the old ones I had backups.

Turns out the new ones are incorrect - or a differently-designed non-oem replacement. They look like donuts instead of a shaped rubber seal. I wondered if the old ones were still sealing properly - in preparation for OUR emission test. Didn't seem worthwhile just reordering the correct seals until I had a bigger order, but maybe I'll pay the extra for the inexpensive seals and get a set at the dealer. Cheap insurance.

Steve
__________________
'91 MB 190E 2.3
'08 RAV4 Ltd 3.5
'83 Lazy Daze m'home 5.7
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 06:21 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, 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