98 7.4 vortec no start

Discussion in 'Chevy Truck Forum' started by jamesl, Aug 4, 2012.

  1. jamesl

    jamesl Full Member

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    troubles again parked the rv a few weeks ago running perfect today will not fire at all tried some starting fluid in intake nothing engine turnes over good no fire on any cylinders and was runing perfect a few weeks ago ? all fuses good , ecm maybe ? are there any aftermarket ignitions that do not require a dealer to program the ecm , I am open for all ideas engine has only 32 k for millage
     
  2. chevychase

    chevychase Semi-Admin
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    Check for spark at dist. cap no spark ..check at coil. Check for power at coil.
    No spark at coil probably the ignition control module ..can take it to auto parts for a test
    Would not think ecm . Do you have a service engine light? Would get a code for bad ecm.
    Here is a link that will help check things good for 7.0/454 also. just click on red link Part 1 -GM Misfire, No Spark/No Start Tests (4.3L, 5.0L, 5.7L).
     
  3. jamesl

    jamesl Full Member

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    it is my understanding power to distritor is tru ecm and each cylinder has a coil , would the icm stop all spark ? no fire at plugs
     
  4. bigred truck

    bigred truck Full Member

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    I have a 99 vortec 7.4 in a truck it has a ignition module and 1 coil for all cyilinder
     
  5. leolkfrm

    leolkfrm Full Member

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    do not use starter fluid!....check around and see if a varmit has been chewing...put a scanner on it
     
  6. chevychase

    chevychase Semi-Admin
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    Yuup a coil pack ..module on these beside the dist. on outside .
     
  7. leolkfrm

    leolkfrm Full Member

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    no he actually has a coil for each cyl mounted above the spark plug on the rocker cover with a 12' wire to the plug...in 98 is when gm made a special build and started using it in the rv chasiss
    depending on the build date there was a recall on the the resister for the air intake and an ecm reprogram
     
  8. chevychase

    chevychase Semi-Admin
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    Icm would kill all spark...So will the crank sensor ..need to test all .
     
  9. jamesl

    jamesl Full Member

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    lastest the engine does have one coil pak , I replaced the icm and still no spark leaving coil I guess the next step is I will change coil pak and the crank sensor and hope one of them works anything hopefully to avoid a tow to the dealership and their 169 per hour labor I relly am surprised there seems to be no aftermarket alternitives , I cut my teeth on carbs and mallory distri
     
  10. chevychase

    chevychase Semi-Admin
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    #10 chevychase, Aug 7, 2012
    Last edited: Aug 8, 2012

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