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 12-05-2008, 02:19 PM
Registered User
 
Join Date: Jul 2003
Location: Bellevue WA
Posts: 176
Fuel line connection to IP

I started to smell diesel fuel driving to work yesterday and then at a stop sign noticed that the engine was running as though it was missing. Then noticed considerable lack of power. I took it to my indy who quickly spotted fuel squirting at the juncture of the fuel line from the IP to one of the injectors. The IP end of the line is a rounded end that fits down into the pump and is brought up tight with a nut. This rounded end did not seem to want to seal to the pump. There had been no recent work and all seperator clips were in place. It just started leaking all of a sudden. Ordered 2 replacement lines at $56 each. Any idea what would cause this?

__________________
87 300D 265Kmi
Factory rebuilt crate 603.96x engine at 200K
Reply With Quote
  #2  
Old 12-05-2008, 02:49 PM
Stevo's Avatar
Registered User
 
Join Date: Apr 2002
Location: NW WA
Posts: 6,299
I wasn't even going to ask, but did YOU try tightening it?
__________________


1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"
Reply With Quote
  #3  
Old 12-05-2008, 05:02 PM
Registered User
 
Join Date: Jul 2003
Location: Bellevue WA
Posts: 176
Yes

Tightened. Repositioned and tightened. No joy.
__________________
87 300D 265Kmi
Factory rebuilt crate 603.96x engine at 200K
Reply With Quote
  #4  
Old 12-05-2008, 05:46 PM
Diesel911's Avatar
Registered User
 
Join Date: Sep 2007
Location: Long Beach,CA
Posts: 51,250
This happens to all Diesel Engines that have Hard Lines to the Injectors ounce and awhile (I replaced 1 one my Volvo).
The longer and thinner the Hard Lines are the more they are prone to cracking.
There has been at least 5 cases in the last 300 or so days on the Forum with cracked Hard Lines.
The biggest cause is vibration (make sure all of the Hard Line Clamps are present and where they are supposed to be; sometimes they vibrate off while driving or the PO misplaced them).
When I was in Trade School I was told that there is at least 2 big pressure waves created in the Hard Lines. 1 when the Fuel is 1st starting to push through the lines and another when the Injector Spray Nozzle closes shut. The shutting of the Spray Nozzle causes a pressure wave to go backwards through the Hard Line.
Now picture this; the Spray Nozzle closes sending a pressure wave backwards (remember the length of the Hard Line Tubing); the backwards pressure wave has not reached the Fuel Injection Pump yet but by now the Fuel Injection Pump is starting to inject Fuel creating another pressure wave going forwards towards the backwards pressure wave! Think of the stress that the 2 pressure waves cause when they meet inside of the Hard Lines.
If your Engine ran at one speed it would be easy to design Hard Lines that would have no problems. (Designers usually try to keep the Hard Lines as short as possible.)
If you look in the Bosh books on Fuel Injection Pumps you will see that they have been trying a bunch of designs of Delivery Valve/spring setups to help cope with the problem but as you see there is no 100% solution.
__________________
84 300D, 82 Volvo 244Gl Diesel
Reply With Quote
  #5  
Old 12-08-2008, 10:52 AM
Registered User
 
Join Date: Jul 2003
Location: Bellevue WA
Posts: 176
New hard lines for #4 and 5 arriving today.

As I said there had been no recent work since the dealer put on a replacement -22 head last winter for the -22 head that cracked. At that time the dealer also resealed the leaks on the IP that had been replaced 6 months previousl to the head. Some of the fuel line clamps were not correctly positioned or inserted completely. So much for dealer expertise!
__________________
87 300D 265Kmi
Factory rebuilt crate 603.96x engine at 200K
Reply With Quote
  #6  
Old 12-08-2008, 10:58 AM
Stevo's Avatar
Registered User
 
Join Date: Apr 2002
Location: NW WA
Posts: 6,299
Would you mind posting which dealer, I dont generally use them but sometimes you don't have a choice. "So much for dealer expertise!" For sure
__________________


1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"
Reply With Quote
  #7  
Old 12-08-2008, 12:48 PM
Registered User
 
Join Date: Mar 2003
Posts: 484
Don`t the new lines need flushing before installation?
Reply With Quote
  #8  
Old 12-08-2008, 05:28 PM
Diesel911's Avatar
Registered User
 
Join Date: Sep 2007
Location: Long Beach,CA
Posts: 51,250
Quote:
Originally Posted by vox_incognita View Post
Don`t the new lines need flushing before installation?
Excellent reminder!
Spray can type Carburator Cleaner with the skinny tube attached or the same but Brake cleaner followed by compressed air from an air gun to blow the lines out good is what I have used in the past.

__________________
84 300D, 82 Volvo 244Gl Diesel
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 02:50 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