help with cummins diesel

Discussion in 'Trucks and Trailers' started by ManleyLawn, Oct 20, 2003.

  1. ManleyLawn

    ManleyLawn LawnSite Member
    Posts: 107

    i was wondering what could cause my fuel mileage to go down to almost 250 miles to a tank? i have a 96 dodge ram 3500 with the 12 valve cummins turbo deisel. it has 137,000 miles on it. i cleaned the air filter checked lines and hosesput additives in the fuel i just can't seem to figure it out. i haven't had a chance to take it anywhere because it is my main truck so any help or ideas would be appreciated. thanks
     
  2. TLS

    TLS LawnSite Fanatic
    Posts: 7,937

    Any large amout of smoke?

    Any Diesel Smell?

    Could have a leaky injector.?

    Winter Fuel? (forgot to look where your from)

    Is your parking brake on?

    :eek:
     
  3. The Lawn Boy Pro

    The Lawn Boy Pro LawnSite Bronze Member
    Posts: 1,217

    Boy, that would be funny! Sure hope its not!!!!!
     
  4. 2 man crew

    2 man crew LawnSite Senior Member
    Posts: 403

    Could be the transmission.:D
     
  5. Lawncareguy

    Lawncareguy LawnSite Member
    Posts: 54

    Holy Cow! That is less than 7mpg! Do you have any excessive smoking? You could have an injector problem or fueling issue on the fueling ECM. I would take the truck to a Cummins truck dealer and have them plug it up and check the codes.

    Too many variables to try and troubleshoot without knowing the codes.
     
  6. ffemt1271

    ffemt1271 LawnSite Bronze Member
    Posts: 1,285

    1. change the fuel filter
    2. get fuel pressure checked rule out lift pump problems)
    4.check injectors
    5.check all hoses and clamps on hoses connected from turdo to cooler and from cooler to engine.
    6. has your fuel station changed to winter fuel blend(usually drops mileage a bit)

    these are some things i thought of. most of them you can rule out your self.
     
  7. ffemt1271

    ffemt1271 LawnSite Bronze Member
    Posts: 1,285

    1. change the fuel filter
    2. get fuel pressure checked rule out lift pump problems)
    4.check injectors
    5.check all hoses and clamps on hoses connected from turdo to cooler and from cooler to engine.
    6. has your fuel station changed to winter fuel blend(usually drops mileage a bit)

    these are some things i thought of. most of them you can rule out your self.
     
  8. blafleur

    blafleur LawnSite Member
    Posts: 229

    Sounds like injectors or lift pump, or both. Very common in Cummins.
     
  9. Randy J

    Randy J LawnSite Bronze Member
    Posts: 1,124

    Actually on the 12 valve, injector or pump problems either one are pretty rare. As a matter of fact, I've never heard of a problem with either on that engine. Now the 24 valve is a different matter - many problems with the fuel pump on it. Didn't you have another thread on this? In that one, most people were saying check the valves - they need to be adjusted about every 30,000 to 50,000 miles on that engine if I remember correctly. The 12 valves were notorious for return fuel line problems, but that usually shows itself as a hard start cold problem. I'd be checking for a fuel leak somewhere though.
    Randy
     
  10. blafleur

    blafleur LawnSite Member
    Posts: 229

    Again, I show my ignorance. This is a good question for dieseltruckresource.com, or turbodieselregister.com.

    Bryan
     

Share This Page