comet running rough (help)

Discussion in 'Technical' started by mavmike72, Oct 5, 2008.

  1. mavmike72

    mavmike72 Member

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    WELL i went from happy to said in a matter of seconds. I put the new injector in started it and you can still pull plug wire off with no change..................im getting Pi$t, now i dont no what to do........................
     
  2. CornedBeef4.6L

    CornedBeef4.6L no longer here

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    did you ohm out the new injector??????? Also I remember you saying you were gonna get a used one.....Tap on it...old ones I have seen the pintle get stuck from just sitting around.....

    While you had the fuel rail off do you look to see if the injectors were spraying?

    The other issue is if that cylinder was running lean.....from a bad injector.......it may have burned an exhaust valve......do a compression test....
     
  3. Bryant

    Bryant forgot more than learned

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    try moving the injectors to different cylinders and use a noid light (a light that plugs into the injector harness plug) to make shure the wireing is good. see if the missing cylinder follows the suspect injector. also is the intake valve opening?
     
  4. mavmike72

    mavmike72 Member

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    Ok here is whats going on went to buddy house first we checked the compression everthing looked good. That mad me happy no burnt valve or bent valve. So the fun started, we took upper intake off and pulled fuel rail off again left the injectors in and turned the key, as it turns out the first injector was spraying. My friend said it should not spray untill the cranksensor tells it too. So we installed another injector. I drove it and it seems better. The only thing now it has a serging (for lak of a better term) at low rpms. When you floor it its ok, pretty good power. But the serging is driving me nuts now.......................
     
  5. mavmike72

    mavmike72 Member

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    All injectors ohmed out ok................I even went to the junkyard and barrowed another mass air meter................just to see if that might be it and no change.
     
  6. LukeDuke

    LukeDuke Member

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  7. mavmike72

    mavmike72 Member

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    Nope checked for that too. Just left his house again checked fuel presure that was good also.
     
  8. Bryant

    Bryant forgot more than learned

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    all the injectors live in the same environment and have worked the same amount of time. if your having problems with one or two dont you think that the rest are not in the best of shape? at this point it would well advised to replace all the injectors.
    also the pcv valve has a tendency to pop out and cause surging on the 5.0 efi motors. check that also.
     
  9. mavmike72

    mavmike72 Member

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    good idea probably going to do that next because im running out of ideas. But the thing that i just cant understand is why i can pull the plug wire off and it doesnt change its been the same cyl all along and im getting fire and its got a different injector aswell................
     
  10. Mavman72

    Mavman72 Gone backwards but lookin' forward

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    How far from the fuel feed to the rail is this injector??? Rail could be plugged.The fuel pressure regulator could be bad and dropping pressure in the rail befor it gets to that injector.I tend to think you have a dead plug,have you tried changing that plug???
     
  11. mavmike72

    mavmike72 Member

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    yes i have change the plug and the wire. Also pulled the wire off plug and its getting good fire......
     
  12. mavmike72

    mavmike72 Member

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    as for as the rail goes we pulled the injectors out of the rail and bumped the key and gas shot out all four injector holes.
     
  13. Mavman72

    Mavman72 Gone backwards but lookin' forward

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    Put another plug in that hole and try it...what kind of plugs are you useing???
    Are you sure that injector is gettig power???As for the surgeing... weak fuel pressure/malfunctioning FP regulator/dirty fuel filter.I have seen Idle air controll motors develope an internal vacuum leak which will cause the idle to hunt(surge)
     
    Last edited: Oct 12, 2008
  14. mavmike72

    mavmike72 Member

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    had champion then replaced with motrocraft. yes on the power ,rented a tester called a noid to test electrical power of injector there all ok.........man i think if tested everything..............its driving me nutssssssssssssss
     
  15. Mavman72

    Mavman72 Gone backwards but lookin' forward

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    Dont use champions.fords eat em alive.
     

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