Topic: cylinder 1 misfire

[roushben]

so i got a 2000 mustang gt and it has a spudder or stumble when accelerating with a noticable loss of power, its been doing this for a while when finally check engine came on and it was p0301 misfire in cylinder one, i just changed all the spark plugs and i havent got to check if its fixed yet becasuse its up on jacks while i put new headers on, how ever i went on a bunch of forums and this seems to be a common problem, and spark plugs never seem to be the problem, i have not seen anyone with a solution to this problem yet so if anyone has any advice i would apreciate it

[Soaring]

The first thing I would do would be to replace the plug wire to the cylinder, then clean the MAF.

[roushben]

already cleaned the maf no improvement.. i was planning on replacing that coil so i will see how that goes..thanks

[phm1178]

2003 Mustang GT 4.6 2V 5 Spd 100K
I just got finished fixing this problem.  Let me start from the begining.  In August i started noticing that I was getting a slight stutter once in a blue moon,  upon acceleration very slight in all of this I never had a problem with idling.  Months go by and this happened here and there finally in November it was very noticible,  but I never got a check engine light so I thought it was bad gas and let it go until it was tank after tank,  finally I got the check engine light about 3 weeks ago,  flashing which told me it was a misfire.  Now this lead me to Autozone to code it for me and gave misfire cylinder 6 and 8.  So it was a sparkplug change and should be done.  Plugs out of cylynder 4 was shredded,  6 a little oily and 8 was fine as were the rest.  After the change car ran perfect for about 2 weeks the began to stutter again,  strange thing was if the car was cold it would run fine for about 10 minutes until it got warm then start to stutter on acceleration.  This was driving me crazy and I started looking through all forums to find out some info.  Same as last time no check engine light.  FInally I read in some post pull the neg battery terminal off for atleast 30 minutes to let the computer reset then go out and drive it u ntil the check engine light comes on,  so I did and it took me about 55 miles before it came on,  back to Autozone and got a code for misfire cylinder 6.  Now I had figured that it can't be fuel because wouldn't that be all the time even at start up?       

[phm1178]

Ran out of characters.  Now I'm no mechanic just using common sense.  So I decided to buy the coil on plug.  It takes 5 minutes to change it just make sure you have a 9/32 socket.  That fixed the problem.  I'm posting this hoping this will help other people with this problem.  Good luck

[Soaring]

Ran out of characters.  Now I'm no mechanic just using common sense.  So I decided to buy the coil on plug.  It takes 5 minutes to change it just make sure you have a 9/32 socket.  That fixed the problem.  I'm posting this hoping this will help other people with this problem.  Good luck

I had the same problem with my 2003 4.6 F-150 truck.  I replaced the #8 coil, and she runs great now.  The codes PO308 Pin point test found #8 coil shorting out. 

[roushben]

that was exactly what it was thanks!

[Soaring]

Glad to help.  #8 is always the culprit because it is subject to the splash from the water on the road becausei it is in the rear of the engine and water gets on it and shorts it out.  If you can somehow fabricate a shield so that will prevent that, you can save yourself a bunch of bucks.  I need to do that as well, so if you come up with a solution, let us know.