[nedo46]

1999 mustang gt 100k miles

when im driving on the fourlane in 5th gear at 55mph (around 1200-1500rpm) when i give it gas it feels like its missing and it only does it when im lugging in 5th gear,

P.s just recently blew a spark plug through the head (cylinder 2) and had to get it rethreaded and i bought a cheap ngk spark plug and cheap coil pack.. do you guys think it just needs a plug or could it be the coil pack or anything else?

[whtpny]

i dunno if it has anything to do with the work you did, but accelerating in fifth sucks.. downshift to fourth lol

[nedo46]

well its never done that before, little things like that just get on my nerves

[xalexg212x]

Originally Posted by nedo46 1999 mustang gt 100k miles when im driving on the fourlane in 5th gear at 55mph (around 1200-1500rpm) when i give it gas it feels like its missing and it only does it when im lugging in 5th gear, P.s just recently blew a spark plug through the head (cylinder 2) and had to get it rethreaded and i bought a cheap ngk spark plug and cheap coil pack.. do you guys think it just needs a plug or could it be the coil pack or anything else?

maybe your clutch is slipping

[prodrifterx]

check coil packs and plugs....mine are weak and going out on me.

at aprox 2k rpm in 2nd gear at 20mph you can feel it and hear it
at aprox 2k rpm in 3nd gear at 30mph you can feel it and hear it
at aprox 2k rpm in 4nd gear at 40mph you can feel it and hear it

swapped my buddies coil packs in my mustang and the problem was gone....i did plugs first and that helped enough so it would set the lite off but it still missed some....99 gt with 50k on it.

gonna order coil packs soon. get good plugs and good coil packs....ford oem coil packs are pricey, more so than gms and msd and accel....that includes boot, connector, and coil pack.

[nedo46]

i doubt its my clutch, i just got a brand new oem clutch installed about 2 months ago

[nedo46]

i replaced the spark plug and coil pack and its still doing it.. anyone have any ideas? i was told it may be the fuel filter but im just gonna change all 8 spark plugs tomorrow to be on the safe side

[whtpny]

Originally Posted by nedo46 i replaced the spark plug and coil pack and its still doing it.. anyone have any ideas? i was told it may be the fuel filter but im just gonna change all 8 spark plugs tomorrow to be on the safe side

have u changed the fuel filter before? are any of your vacuum hoses looking bad?

[prodrifterx]

do the fuel filter and all 8 plugs....if it still does it....move the new coil around til you get it to go away....start with #1 cyl....if thats not it then pull #2 and put the oe coil back in #1 and the new coil in #2....use the new coil to find the weak coil. i had to do this sunday. #4 and #2are weak on my car.

[nedo46]

Originally Posted by prodrifterx do the fuel filter and all 8 plugs....if it still does it....move the new coil around til you get it to go away....start with #1 cyl....if thats not it then pull #2 and put the oe coil back in #1 and the new coil in #2....use the new coil to find the weak coil. i had to do this sunday. #4 and #2are weak on my car.

was yours acting like mine?

[04GTAMPA]

missing or jerking? I guess it's the same huh?

[prodrifterx]

yes the same...yes both one coudl describe it as..yet its missing. after my play day sunday of diag its running ok...but still misses...not as much but thats bc i was fooling around with the coils and the electrodes....im ordering accels today.

also a ford dealer will say only motorcraft...yet i changed plugs to bosch....and its still did it....so it dont matter about the plug really...given all thngs constant and no change in harshness or timing of the missing.

do all plugs...then reevaluate...then maybe coils. talked to a few buddies that work for ford...they say they occasionaly have to do both plugs and coils....mos cases only plugs...but theres always a fluke or that one time that a car needs both.

[sxynerd]

What ever it is it's spark related. A Fuel filter wont cause that. Since you just blew out a plug I would say it has something to do with that. Use your DMM and a Chilton or Haynes to measure the resistance in on the COP's. COP are notorious for failing... Time for an upgrade, I'd imagine.

Accels are cheaper than Factory replacements and MSD's suck.