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Is there an in tank pump?

Discussion in '1982-Present GM Diesel' started by Pookster, Apr 17, 2004.

  1. Pookster

    Pookster 1/2 ton status

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    been looking at running the straight veggie oil conversions , with a seperate tank, none of the conversion units ever talk about " a pump". So i assume, that there is none, and that the only pumps are the injector pump, and the lift pump which somehow sucks the fuel from the tank.

    Does this seem right?
     
  2. bigblock454

    bigblock454 Clack Clack Clack Premium Member

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    Non of the factory GM 6.2/6.5s had in-tank pumps. Lift and IP did all the pumping.
     
  3. Pookster

    Pookster 1/2 ton status

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    So in theory, I could have a rubber hose dippin into a 55 gallon oil drum and just let it get sucked out? (obviously priming the line so that there is no air in it)?
     
  4. bigblock454

    bigblock454 Clack Clack Clack Premium Member

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    Assuming the veggie oil is good and warm and the connection to the tank was on the bottem (assuming the tank was in the bed). When the oil becomes cold you may have some problems pumping it.
     
  5. Pookster

    Pookster 1/2 ton status

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    Not to seem like a moron, but... After I shut down my truck, I seem to hear some noise from the rear for a few moments. The sound seems like a fuel pump! Almost like a mild hum. Funny thing is, I dont hear it during the pre-start phases!
     
  6. bigblock454

    bigblock454 Clack Clack Clack Premium Member

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    It kinda makes sense. In the 6.2/6.5 Diesels fuel is circulated from the tank to IP to Injectors back to the tank. If you were driving for a while you probably heated the oil up reducing it's thickness allowing for a more noticeable pump noise when warm.
     
  7. Pookster

    Pookster 1/2 ton status

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    Kinda Lost. Previously it was stated that there is no "in tank pump".

    Ok, the fuel heats up from circulation, that makes sense.

    But if there is no pump in the tank, why am I hearing it? is there a supplimental pump somewhere along the system?
     
  8. bigblock454

    bigblock454 Clack Clack Clack Premium Member

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    No in tank pump. Depending on the year of your truck you may have an inline electric "Lift Pump" located on the frame rail under the drivers side door.
     
  9. Pookster

    Pookster 1/2 ton status

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    That must be the noise im hearing. i'll crawl under and check it out tomorrow.
     

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