Luther Gulseth wrote:
My SD has it's moments of fuel pressure loss.  You can be crusing down the 
interstate and suddenly feel a power loss that lasts less than 1/2 
second...something exactly like taking your foot off and back on the throttle.  
Also, at cold start it's very rough and needs to have enough throttle to keep 
at least 800-900 RPM to run somewhat smooth and not die.  Glow plugs are barely 
2 years old and the injector pump and injectors were replaced by the P/O (maybe 
50kmi ago).  I've replaced all the rubber fuel line from tank to primer in the 
last 8 months.
I'm thinking from my experience in the semi-diesel world that I have a lift pump that's 
weak.  I read 07.1-145 "Checking fuel pump and bypass valve" and it seems that 
the bypass valve can get clogged and needs to be cleaned and the spring lengthened to 
increase tension.  Is there anyone else that has had an issue similar to this where 
cleaning the bypass valve fixed the issue or did they have to replace the fuel pump?

(btw fuel, primer, & lift...they all mean the same thing in the big diesel 

TIA all,

The "lift pump" almost never fails (and the engine will still usually run if the fuel level is above 1/2)!! Look at the tank screen, the inline filter, the main filter or a plugged VENT line. A plugged vent line is the thing that most often causes the symptoms you describe in a Mercedes diesel (vacuum develops and prevents unrestricted fuel flow).

          Marshall Booth (who doesn't respond to unsigned questions)
      "der Dieseling Doktor" [EMAIL PROTECTED]
'87 300TD 182Kmi, '84 190D 2.2 229Kmi, '85 190D 2.0 161Kmi, '87 190D 2.5 turbo 237kmi

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