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1997 mustang cobra problem please help

Discussion in 'SN95 Cobras' started by Phillip Scocca, Aug 7, 2019.

  1. Makobra

    Makobra Well-Known Member Established Member

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    get the exact time it takes for it to start running bad. time it and post that time here.
     
  2. Phillip Scocca

    Phillip Scocca Member Established Member

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    My brother had friend who’s a mechanic come to the house they compression tested it said it was good he said the wiring harness ? Any idea if that would do this to the car
     
  3. Makobra

    Makobra Well-Known Member Established Member

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    is the car lowered?
     
  4. Phillip Scocca

    Phillip Scocca Member Established Member

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    the car is not lowered it’s stock height
     
  5. Makobra

    Makobra Well-Known Member Established Member

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    well crap. you've gotta put a computer on it and see what its doin, man.
     
  6. Phillip Scocca

    Phillip Scocca Member Established Member

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    I just hooked the scanner up and finally got a reading cylinder 8 misfire P0308 , I unplugged the mass air flow sensor and the car continued running no different.
     
  7. Makobra

    Makobra Well-Known Member Established Member

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    swap the coil pack on that cylinder and if it continues disconnect the fuel injector wires from the injector on that cylinder.
    I suspect you have a leaky or bad injector or a bad coil.
     
  8. Phillip Scocca

    Phillip Scocca Member Established Member

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    The coils and plugs and wires are brand new , we changed the coils around still the same, is it possible it’s a dead cylinder
     
  9. Makobra

    Makobra Well-Known Member Established Member

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    if your compression is good and your coils are good and your plugs are good when that only leaves the injector being bad.
    there is no such thing as a "dead cylinder". all you need to run is compression, fuel and spark.

    disconnect the injector and see what happens. if nothing changes or it just runs worse then i'd put money on that.
     
  10. Phillip Scocca

    Phillip Scocca Member Established Member

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    The injectors were done last year and were just recently cleaned another code came up p0351
     
  11. Makobra

    Makobra Well-Known Member Established Member

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    Code says bad coil, car acts like bad coil, I say it's a bad coilpack.

    I'd pull the plugs and put a scope down the cylinders. One will probably loook quite different. Might even be a clean spark plug if they were new when this happened.
     
  12. Phillip Scocca

    Phillip Scocca Member Established Member

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    Both coils packs were replaced also swapped them and still throws number 8 misfire
     
  13. Makobra

    Makobra Well-Known Member Established Member

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    unplug the coil pack on number 8 and see if it says the same thing.
    also, get a camera from harbor freight and look in the cylinders.
     
  14. Phillip Scocca

    Phillip Scocca Member Established Member

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    Okay will do , what am I looking for with the camera ?

    Thank you for the help
     
  15. Makobra

    Makobra Well-Known Member Established Member

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    you are looking for the cylinder that looks different. each cylinder should look the same. if you have one that isn't firing at all or is randomly firing it'll look either a lot cleaner (because gas will be acting as a solvent) or it might look VERY dirty because the fuel mixture is wrong for that cylinder so maybe excess soot compared to the other cylinders. its hard to explain but in general when troubleshooting systems what you need to look for are differences between similar things.
     
  16. Tillerman77

    Tillerman77 Active Member Established Member

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    What brand of plug wires? I ask because many forum members have had problems with FRPP wires.
     
  17. Makobra

    Makobra Well-Known Member Established Member

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    oh crap i forgot the 97's had plug wires (i have a 99 motor). my bad. yeah check those.
     
  18. Phillip Scocca

    Phillip Scocca Member Established Member

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    There are stock autolite coils and wires on the car
     
  19. Makobra

    Makobra Well-Known Member Established Member

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    welp, they are suspect. next on the list is your wiring harness.
     
  20. Phillip Scocca

    Phillip Scocca Member Established Member

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    Is it hard to do a wiring harness ?
     

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