Dreaded MISFIRE!!!

Discussion in 'Engine & Performance' started by Venomized, Oct 11, 2012.

  1. Venomized

    Venomized Full Access Member

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    A little history here:

    1998 f150 reg cab short box XLT
    4.6L/auto
    Coil packs not COPs

    Bought the truck about a year ago for cheap. Needed tires, rear wheel bearings/seals, had a misfire. Started slow and easy with the wheel seals and bearings. Once that was done I put new plugs and wires in. Then new tires. Also did fuel filter as well for good measure.

    After ~ a month or so the misfire came back. This time in full force. I went to vatozine and had the codes ran. i got 2 misfires #4 and #7 along with an EGR code (i cleaned out the EGR after) and rear O2. I swapped wires for new, plugs for new, and coil packs for new to no avail. This weekend im gonna try cleaning out the motor with seafoam and do a comp test. If that has no effect i will do a borescope (if someone i know has one) to see if anything down where i cant see is bad.

    Any other ideas??

    Im actually very mechanically inclined and have worked in the field. Just trying to get advice since we all know this is a common issue.

    Going to add this so everyone knows the sypmtoms:
    Rough idle
    No power on take off
    Misfire codes

    Thing i have done:
    New plugs TWICE
    New wires TWICE
    New coil packs
    New injectors
    Tested power to injectors and everythings good
    Seafoam
    Higher octane gas
     
    Last edited: Oct 14, 2012
  2. iowaredneck

    iowaredneck Administrator

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    Try seafoam and could have bad cop or plug
     
  3. cowboy

    cowboy Sheriff

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    not a bad idea I'd swap your cop around and see if the problem follows.
     
  4. Venomized

    Venomized Full Access Member

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    Edited the original post sorry lol. That info might help
     
  5. AKBray907

    AKBray907 SUPER *********.

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    Guarantee it's a COP, had this happen before. Easy fix an they wear out, not super cheap though.
     
  6. AKBray907

    AKBray907 SUPER *********.

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    Just a heads up incase you hadn't heard before a cop is coil on plug , it's the ignition coil for each cylinder. Just incase you hadn't heard that term before
     
  7. Venomized

    Venomized Full Access Member

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    Ive heard it belive me. This truck has the coil packs not COPs and after changing coil packs it didnt help any.
     
  8. AKBray907

    AKBray907 SUPER *********.

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    I just realize you had a 4.6. Which plugs did you use
     
  9. AKBray907

    AKBray907 SUPER *********.

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    Post a video of whats happening
     
  10. Venomized

    Venomized Full Access Member

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    I used NGK plugs (ive used them on all my vehicles). As far as a vid, im at work but will shoot and post one tomorrow.
     

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