Question about 1999 Ford Crown Victoria

1 Answer

My 1999 crown victoria is misfiring at high speeds even after i changed all coils and put the right gapped spark plugs in i had it checked on a scanner and it said cylinder 5 was misfiring so they took the plug from 5 and switched it with 6 and told me to drive it for a couple of days and when i came back cylinder 4 was misfiring its only doing it at high speeds and i already cleaned the MAF i never had this problem untill they changed the plugs

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  • Anonymous Mar 18, 2010

    i did twice i even put a new set of plugs in and the coils are all in tack and on the plugs perfectly unless theres a problem with the new coils which i doubt

  • Anonymous Mar 18, 2010

    so why would it be misfiring only above 50mph if the firing order isnt correct

  • Anonymous Mar 19, 2010

    oh ok lol the only other code is something about bank 2 in the exhaust but that was like that waaay before it started running like that and thx for the idea about the crank sensor but it says When a crankshaft sensor has failed or is failing, certain timing problems will arise in engine function. The engine may start normally in some cases, but will cut off after a few minutes (or seconds) of operation. More than likely the engine will be unable to start at all. Since the crankshaft sensor is responsible for engine timing, the driver may experience engine backfire or irregular rpm function, if the vehicle starts at all and thats not whats happening im getting a skipping above 45 mph

  • Anonymous Mar 20, 2010

    ive read pretty much everything on the internet on this topic lmao but im goin tuesday to the ford dealer to get a coil stress test cuz i think 2 of 8 of the new coils might not be good so wish me luck plus i still have the receipt so all i have to pay is for the test

  • Anonymous Mar 20, 2010

    ill def. let you kno thx for the good luck ill get back to you this tue

  • Anonymous Mar 20, 2010

    remember that website you told me about on autozone i found this

    Feels Like
    Symptom: Misfiring
    When: At High Speed
    Where: Engine Change

    Priority Action Part Type Cause
    1 Inspect Timing Specification Incorrect Ignition Timing.
    2 Inspect Spark Plug Fouled, Damaged, or Broken Spark Plug(s).
    3 Inspect Distributor Worn, Damaged or Faulty Distributor.



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  • Master
  • 775 Answers

Not only did the problem switch cylinders, it switched banks. cylinders 5&6 are on the drivers side and 4 is on the passenger side. i would recheck all wires to make sure you have the correctly installed.

cylinder locaton
2 8
dr. 8 7 6 5 7 4 coil

pass. 4 3 2 1 3 5
6 1 coil

Posted on Mar 18, 2010

  • 5 more comments 
  • toneman2121
    toneman2121 Mar 18, 2010

    although this diagram is marked MUSTANG, it is identical to the cv 4.6l

  • toneman2121
    toneman2121 Mar 18, 2010


  • toneman2121
    toneman2121 Mar 19, 2010

    obviously i had the wrong diagram. you have coil on plug ignition, correct? in any case, all your coils, plugs and wires are new. the computer tells the coils when to fire. and the computer receives input from the crank sensor. maybe at that speed the sensor isn't reading right. try cleaning the sensor. is there any other codes showing up? you can go to for a look at engine and ignition circuits.. and just about anything else you need as far as repair goes. register and enter your vehicle. go to repair guides. then go to ignition system.

  • toneman2121
    toneman2121 Mar 19, 2010

    check for vacuum leaks.

  • toneman2121
    toneman2121 Mar 19, 2010
  • toneman2121
    toneman2121 Mar 20, 2010

    yeah man, you need some equipment to test this fault, i have a 97 cv. it had a mis and it was bank 2 coil pack. easy. please let me know what's up! i still think it's a air leak. i'll be glad to be proven wrong. good luck!

  • toneman2121
    toneman2121 Mar 20, 2010

    alrighty then!



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