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  1. #1

    Default 1996 7.4 suburban will not start

    HELP!!!!! I have a 96 Suburban 7.4. I was driving a month ago and stopped at the light. When I pushed the gas it lunged and quit. I have changed the timing chain and gears, Plugs, Wires, Cap, Rotor, Cam Sensor, Crank Sensor, Fuel Filter, Fuel Pump and have no change. It acts like it wants to start but it will not fire. I have 56 psi at the plenum with the new pump. I am not getting any codes when a plug it into a code reader. Any suggestions as I am stumped.

  2. #2

    Default

    Are you getting fuel to the engine? Are you getting spark at the spark plugs?



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  3. #3

    Default

    I have 56 psi at the plenum and I pulled the #1 plug and checked the spark and it is ok.

  4. #4

    Default

    Next question would be since youve got spark at the cylinder and fuel at the cylinder are you getting spark and fuel at the right time.
    I see where you replaced parts, were any of these parts known bad and identifiable as contributing to the original problem or is the present no start condition a continuation of the issue?

  5. #5

    Default

    We know you replaced theses parts, but did you make sure all of them are plugged in all the way or the harnesses may be damaged. just having a crank sensor unplugged will cause the truck no to start.

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  6. #6

    Default

    The only part I know for sure was bad is the timing chain. It had jumped a couple teeth and is now correct. The other parts have just been a quest to try and get it to start.

  7. #7

    Default

    Ok jumping time was the original issue.
    Did you check the valvetrain when you assembled the new parts?
    The 7.4 is an interference engine, to not get valve damage after jumping time would be lucky.
    Is it possible your 180 out?

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