The GAC Truck

  1. Chevy305

    Chevy305 6 Lug 14bsf Status Premium Member GMOTM Winner

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    More progress on the TBI swap:

    IMG_20191113_150534.jpg

    Unfortunately, I think the ECM might be toast. It isn't activating the fuel pump relay. I have verified the fuel pump and wiring works with the red jumper connector at the relay, I can also jumper out the oil pressure sensor connector and get the pump the run.
    Even with the relay jumpered out, it still won't fire the injectors. I can get it to run with starting fluid so I know I have spark but no fuel pump or injectors firing... I'm thinking ECM, thoughts?
     
    Last edited: Nov 19, 2019
  2. imiceman44

    imiceman44 Hoarder extraordinaire Premium Member

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    I would be inclined to think so
     
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  3. Chevy305

    Chevy305 6 Lug 14bsf Status Premium Member GMOTM Winner

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    It runs!!!!!!

    Turns out I missed a splice in the harness and the ECM wasn't seeing ignition 12v+ signal. Fixed the splice and it fired right up!
    I just need to get a proper throttle bracket and install the O2 sensor and I can be driving down the road.

    Next summer I'll actually swap in the ESC distributor. I'll plow this season as fuel only TBI.
     
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  4. Chevy305

    Chevy305 6 Lug 14bsf Status Premium Member GMOTM Winner

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    More progress! Got a bunch of odds and ends wrapped up like the O2 sensor, throttle bracket, and wiring wrapped up.


    I drove it to the gas station and it runs and drives great! Idle is more stable and I picked up some more mid range power. It's not as smooth as a factory TBI truck but I didn't expect it to be with the carb intake, adapter, HEI distributor, and the cam isn't the same as the TBI ones. However, I will say it's better than the Holley and the Qjet I had on there especially during cold start and warm up.
    The only weird thing is the idle is a little low when warm. So I just looked up the procedure to set the idle so I'll do that when I get the time after the snow storm tonight and tomorrow.

    I'm very happy that she's ready to go:

    IMG_20191201_105419.jpg
     
    max 02, KirsL, Truckman4life and 4 others like this.
  5. Smokinthehippies

    Smokinthehippies 3/4 ton status Premium Member GMOTM Winner

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    Nothing like a Sunday evening book report. Got her finished up the day before the snow lol.
    Good job though. I bet it will keep pulling its weight great.
     
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  6. 79rustyk10

    79rustyk10 3/4 ton status Premium Member

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    I have a TBI intake, and cam that will be coming out soon if you want. Free to a good home, or bad home, or whatever.
     
  7. Chevy305

    Chevy305 6 Lug 14bsf Status Premium Member GMOTM Winner

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    Thanks but I have a TBI intake for it on my work bench. I threw an adapter on it because it was easier than swapping the intake... Lol


    On a side note, the GAC truck plowed flawlessly today. :woot:
     
  8. Chevy305

    Chevy305 6 Lug 14bsf Status Premium Member GMOTM Winner

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