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gas tank help

Discussion in 'The Garage' started by BL1TZKRIEG, Sep 8, 2005.

  1. BL1TZKRIEG

    BL1TZKRIEG 1/2 ton status

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    I have a 90 fullsize blazer
    I need to remove my gas tank and need to get all the gas out.
    I tryed siphoning but I couldnt get the hose down all the way

    is there a way I can hot wire my pump? like using the diagnostic port under the dash ? so I can just pull the hose and let it pump into a gas can

    also since I will be having my tank out I want to replace the fuel pump, what is the best and most reliable brand ?
    also is it worth replacing the sending unit ?
     
  2. crazyhole812

    crazyhole812 1/2 ton status

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    can you take your fuel line apart at a hose and let your pump run? i think it will run until it gets pressure if hose is not hooked up it should keep running
     
  3. dyeager535

    dyeager535 1 ton status Premium Member

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    Yeah there is a diagnostic port on the ALDL connector for forcing the fuel pump to run, at least on the TPI setups. There is a post I made on here with all sorts of diagnostic stuff and I think it's got a link to the ALDL pinout. Just search title only for "troubleshooting" using my username and it will come up.

    Also there is a lead for you TBI guys right off the fuel pump relay you can put power to.
     
  4. spearchucker

    spearchucker 1/2 ton status

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    Nope, I tried that once so I could fill a 2 gallon gas can when I was way out in BFE one time. The pump only runs for 3 or 4 seconds to pressurize the system then shuts off. Then you have to wait for about 15 seconds before you can do it again. It took forever to get 2 gallons out of it.
    What you can do is disconnect the wires that go to the gas tank. It's located on the driver's side frame rail at the front of the tank. One of the wires is for the sending unit, the other is the positve for the pump, but I forget which is which. You'll need to take a voltmeter and probe each wire to find out which on is the 12V. Just turn you key to the accessory position and you'll get a 12V reading for a few seconds (system priming). But like I said, if you miss the reading you need to wait 15 seconds before you can try again. When you find out which is the right wire, find the corresponding wire on the plug that goes to the tank. Then hook up a 12V source to that wire and the ground to the frame. Disconnect the line going to the fuel filter and run that into your storage tanks.
    AC Delco pumps seem to have a good reputation and they come with the sock too. I think mine was about $50 if I remember correctly.
    I wouldn't replace the sending unit, it costs a couple hundred. If you think it's reading bad then look for the post from yesterday.
     
  5. spearchucker

    spearchucker 1/2 ton status

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    DAMN YOU ! :D
    I wish I knew you were responding or else I wouldn't have spent 10 mins typing something up. :rotfl:
     
  6. BL1TZKRIEG

    BL1TZKRIEG 1/2 ton status

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    thanks for the replies :)
     
  7. BL1TZKRIEG

    BL1TZKRIEG 1/2 ton status

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    [​IMG]

    so could I put a paper clip in the G and the A terminals
    and would the turn my pump on ?
     
  8. dyeager535

    dyeager535 1 ton status Premium Member

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    Should, first check that your ALDL is wired up for that. Not all of the ALDL's have all of those wires of course.
     
  9. BL1TZKRIEG

    BL1TZKRIEG 1/2 ton status

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    I checked in my manual to make sure it's the G terminal
    so can I just ground it to the A terminal

    or should I try to do it from the fuel pump relay ?
    thanks for the help :)
     
  10. Blue85

    Blue85 Troll Premium Member

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    I know this post is old, but I was just wondering why you wouldn't stick a jumper in the fuel pump relay socket. You could either run the power through the jumper or ground the - side of the coil to turn the relay on.

    Something else that could work is to jumper across the oil pressure switch, but that's probably harder to get to.
     
  11. dyeager535

    dyeager535 1 ton status Premium Member

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    You are talking about jamming something in the "back side" of the connector for the relay?

    Just saw a post the other day regarding the single "test" wire that hangs off the relay plug. Add 12V to that (right TBI folks?) and the pump runs. Thats the way I'd go, although my TPI doesn't have that test wire, and I've got a paperclip for the ALDL in the cab. :)
     

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