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Thread: No Spark and car wont fire up PLEASE HELP!!

  1. #1
    Potential Tuner
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    Oct 2018
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    No Spark and car wont fire up PLEASE HELP!!

    Hello all. I have a problem that has been driving me absolutely nuts.

    I have a built 6.0 LQ9 running a SD Open loop tune. It has been running for about 6 months now with no issues until now. The car turns over and it seems to want to start up but it does not fire up. We tested for spark using the in line spark tester and it does not have any spark. We changed the crank sensor to a brand new one and same with the crank sensor. Also checked the injector pulse with a noid light and the injectors seem to be working fine. Also, we tested for power at the coil packs and the coil packs are getting power through the pink wire in every single one of them. We tried to put on different coil packs and still the same problem persisted. We even checked the ignition relays and swapped them with fan relays and no luck. Even tested the relays to make sure that they worked and they seemed fine as well. Fuel pressure is also good. Reading around 55 psi at resting and 53 psi on cranking. I am at a total loss on where to even start next. Attached is a log file that i took when cranking the motor over but not starting. Maybe you guys can pick something up that i can't. I need some big help here. Thank you all in advance.
    Attached Files Attached Files
    Last edited by mesmurize; 10-20-2018 at 03:31 AM.

  2. #2
    Potential Tuner
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    Anyone please?

  3. #3
    Tuning Addict 5FDP's Avatar
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    May 2012
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    Rogers, MN
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    Post tune.

    That log doesn't really give any information as to why it won't start.

    You could have the wrong settings for speed density or even a security issue causing it to not fire.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  4. #4
    Potential Tuner
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    Quote Originally Posted by 5FDP View Post
    Post tune.

    That log doesn't really give any information as to why it won't start.

    You could have the wrong settings for speed density or even a security issue causing it to not fire.
    The car has been running for about 6 months on this tune. and all of a sudden it wont fire up, so i highly doubt that it is anything in the tune... but here it is. Just for clarification as well, i changed out the cam sensor and the crank sensor to brand new modules and i still have no spark. Also, my noid light that i hooked up to the injectors gets signal but very very very faint and does not consistently pulse.
    Attached Files Attached Files

  5. #5
    Tuner in Training
    Join Date
    Mar 2017
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    Did you ever solve this? I have a 2003 Silverado with a 408 build. Was running fine for 2 months then just died, now no spark.

  6. #6
    Potential Tuner
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    Jun 2019
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    Camshaft Position Sensor

  7. #7
    Potential Tuner
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    Jun 2019
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    Also check all your grounds.