#2 cyl. misfire....why?

Discussion in 'Fox 5.0 Mustang Tech' started by Killer50stang, Aug 12, 2006.

  1. As stated, I've pulled codes and found 2 cyl is misfiring. I have all new plugs and wires. What else could this be?

    Jason
     
  2. did you check the dist. cap? It could be faulty.
     
  3. The only thing that wasn't changed was the cap/rotor.
     
  4. An injector? Test for pulse with a noid light. If you have a mechanical stethescope you can hear if its clicking or not.
     
  5. Do a compression test as well. If you have a dead hole then it's not gonna fire. You could have a blown head gasket, broken valve spring, bent valve, collapsed lifter, things like that
     
  6. New plugs since finding the code, or you did new plugs and got a miss? If you just installed the plugs, pull #2 and make sure the ceramic didnt crack during the install. I always buy 9 plugs when I do 'em for that reason.

    Otherwise, the guys have you covered with the biggies - compression, fuel and spark.

    Good luck.
     
  7. I got the misfire after the install, but this is a new car and I always do a tuneup when I buy them, because I never know if they were changed before. Just something I'm picky about. The wierd thing is, it doesn't do it all the time. Engine light comes on every now and then. If I had things stated above, wouldn't it be on all the time? Also, when it does happen, it seems the car pulls back and forth when driving. Any other clues?
     
  8. Since the CEL comes on, pull the codes to see if it gives an idea about the issue.

    I agree that if it's not a constant miss, it's not a hard part failure. But something like an issue with a plug wire is quite possible.
    You can check wires for leakage.

    Good luck.
     
  9. Wires are brand new...
     
  10. New wires doesnt mean that one isnt cross firing or grounding out.

    As mentioned, I'd first rule out a bad wire (swap wires and see if the issue follows the wire). Then do a quick compression test on that pot. Then if you have a noid light, check for pulsing.

    Those are the biggies to check and testing will take about 15 mins for all of it.

    Good luck.
     
  11. First off, check your plug, then check your wiring at night time, you will be able to see if it grounds out. After that do a compression test. I went through some MAJOR headaches tryin to find the problem to my dead cylinder. It ended up being a collapsed lifter.