Whats involved in wiring my 73 blazer for a tbi engine

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 73K5Kid, Oct 11, 2002.

  1. 73K5Kid

    73K5Kid 1/2 ton status

    Sep 24, 2002
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    chandler az
    I know this has probably been beat to death. Does anyone have instructions on how to do this or where do I get them. I have a 1988 wiring harness and computer out of a truck. I know I will have to run a electric fuel punp and o2 sensor. Is this a difficult swap. I know basic electrical and my dads a General contractor and knows more about electrical then I do. He doesn't know it yet but he will be helping with the swap. Thanks for all replies
  2. Chris Demartini

    Chris Demartini 1/2 ton status

    Feb 17, 2000
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    Dumont NJ 07628
    <font color="blue">Most of the wiring in an EFI system (such as the O2) is between the ECM and it's related components, there is very little splicing into your factory system. All you need to do is hook the harness up to a few battery power sources, a couple ignition sources and splice 1 of the wires into your ignition trigger. An auxillary fuse block like the Circuit Boss from Painless wiring will make this very simple and clean. The better the more complete and un-hacked your harness is, the easier this will be
  3. azblazor

    azblazor 1/2 ton status Premium Member

    May 5, 2001
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    Arizona, Phoenix area
    Put some more info in your profile. Where in Phoenix are you.

    I have done this conversion before. Its not hard but you need to have, and read, and understand the wiring schematics for your truck and the donor truck, in my opinion.

    Off the top of my head:

    For the interfaces from the truck to the new system you need to:
    transfer the distributer power wire to the TBI distributer,
    power 2 inputs to the computer,
    wire in a park/neutral switch into the computer,
    wire in a brake switch into the computer,(lock up torque convertor)
    get a VSS signal into the computer,
    wire in an ALDL connector for diagnostics (they get cut off most of the time when the harness is removed),

    For the computer/engine harness you will need:
    the O2 sensor installed,
    knock sensor installed
    all sensors on the intake manifold (TPS, ESC, MAP, etc)
    oil pressure sensor
    water temperature sensor

    Also you are aware of the fuel pump and return line. You also need to adapt the TBI "carb" and sensors onto your intake manifold or you need to modify the TBI manifold for the 4 center bolts to mate to your heads.
  4. dyeager535

    dyeager535 1 ton status Premium Member

    Dec 13, 2000
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    Roy WA
    You kind of covered it, but TBI sending unit as well : )

    Baffled fuel tank is a nice idea, but apparently not necessary. I'm doing it to be on the safe side. $130 aftermarket for a baffled steel tank.

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