I was changing my plugs today to get rid of a sick misfire I had and i noticed that the boots on two of my coil packs have slits in them. Does anyone think that these could be causing my misfire. after the plug change, most of the misfire is gone. Now there is just a slight hesitation below 2000. Before, the misfire was all over the powerband...Any thoughts?

 

I always replace the boots when i change plugs on the 5.4's at work.they arent real cheap but can save headaches down the road.Those boots with slits could very well cause a missfire.make sure you tork in the plugs good cause you dont want em to loosen up and blow out..........................Gary99gt

 

Any brand in particular-I've seen the Granatellis and the Accels.I've heard more about the Granatellis in these cars, but I know Accel has been around for a long time-still no clue though...

 

i think the rubber is there to help keep the conductive part of the coil pack cooler, since spark plugs emit a lot of heat. so when you get cracked/slits, it doesnt help as much. i could be wrong but.

does it happen even if the cars cold?

 

I always run the autolite stock plugs.Those boots keep the high tension voltage from arching ground to the head.There is that spring off the coil that acts like a wire.Some guys might prefer the aftermarket plugs but mostly I use the ford brand............Gary99gt5sp