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Thread: Injectors not pulsing...

  1. #1
    Fuel Injected! mytmouz's Avatar
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    Injectors not pulsing...

    Doing a GM tbi swap, and I am using a 1227747 computer, and what is supposed to be a 1989 truck harness. (I say supposed to, because I am finding the factory fuel pump relay wiring colors and pinouts to be different than what I am seeing on the prints here, which is not unusual). I have fuel, as pressure is to tbi. I have spark, as I can dribble fuel in the tbi and it runs. What I don't have is the injectors cycling apparently. I have verified all the constant grounds to the computer so far, and the switched/constant 12 volt wiring as well. Oil pressure cutoff switch is bypassed, all other stock stuff is in place such as EGR, etc. Did a quick search, but didn't see an injector thread, although I probably missed it. Hoping someone could point me in the right direction.The swap is a 350 Vortec engine, all stock, with the GMMP TBI swap intake, in a 1989 D21 Nissan pickup, by the way...

  2. #2
    Super Moderator Six_Shooter's Avatar
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    Do you have a way of datalogging through the ALDL connection? If so, we can start there.
    The man who says something is impossible, is usually interrupted by the man doing it.

  3. #3
    RIP EagleMark's Avatar
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    If you have spark... hmmm... do you have power to injectors? The wires to ECM are grounds for them.

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

  4. #4
    Fuel Injected! mytmouz's Avatar
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    Quote Originally Posted by Six_Shooter View Post
    Do you have a way of datalogging through the ALDL connection? If so, we can start there.
    Not at this time. Was looking at a thread about one to use a usb port. Need to see what else is involved.
    Last edited by mytmouz; 05-01-2013 at 01:18 AM.

  5. #5
    Fuel Injected! mytmouz's Avatar
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    Quote Originally Posted by EagleMark View Post
    If you have spark... hmmm... do you have power to injectors? The wires to ECM are grounds for them.
    My plan is to start tracing the injectorsagain. I did them the first time with no guide, just with harness laid out. The pdf I found on here will hopefully help.

  6. #6
    Super Moderator Six_Shooter's Avatar
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    Quote Originally Posted by mytmouz View Post
    Not at this time. Was looking at a thread about one to use a usb port. Need to see what else is involved.
    It would be a good idea to get that soon, seeing of the ECM is getting DRP, and other signals can shorten diagnostic times by quite a bit.
    The man who says something is impossible, is usually interrupted by the man doing it.

  7. #7
    Fuel Injected! mytmouz's Avatar
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    Quote Originally Posted by Six_Shooter View Post
    It would be a good idea to get that soon, seeing of the ECM is getting DRP, and other signals can shorten diagnostic times by quite a bit.
    I am not a techie, so I am not sure what all is involved. Trying to search for myself, but I work a LOT (last day off was Easter, lol) so it is a slow go...

  8. #8
    Fuel Injected! mytmouz's Avatar
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    I got it fire up. Didn't run it long, as I have no exhaust. Going to clean up/wrap the wiring, mount the ECM, etc. Then get some pipes. I am sure I will have some more questions by then, lol... Thanks for the help and the wiring diagrams.

  9. #9
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    injectors not firing 1227747 ecm

    Quote Originally Posted by mytmouz View Post
    I got it fire up. Didn't run it long, as I have no exhaust. Going to clean up/wrap the wiring, mount the ECM, etc. Then get some pipes. I am sure I will have some more questions by then, lol... Thanks for the help and the wiring diagrams.

    Im having the same problem, what did you do to finally get ur injectors to fire?

    Any help would be awesome.. -Tyree

  10. #10
    Fuel Injected! mytmouz's Avatar
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    I had inadvertently left a wire unterminated.

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