Some background on the issue.

I have an 03 with the 5.4 and about a month ago I sprayed off the motor after riding the refuge after doin this it caused a miss on my number 3 cylinder. So I bought a new coil but by the time I was going to put it on the misfire stopped so I didn't change it. Which comes to now. After my truck sat for a couple days during thanksgiving break I had to come back to school, after driving about thirty minutes I made a stop and when I went to leave that misfire returned but went away after a couple miles. After some time the misfire came back but went away after a mile or two.

None of the wires feel or look loose. Is this a fouled spark plug or a retarded coil? I always thought when a coil went bad it was dead for good. Any help would be greatly appreciated.

 

The cop's are sensitive to water, very. If you have to spray your engine off, you want to protect them. For now, they are probably fouled. I would pull them all off, remove the boots and let them dry out. Hopefully you can salvage them. If they have a lot of miles on them, consider them to be replaced.

 

I ended up replacing the cop and blowing the well out on the number 4 cylinder. It would be the hardest one to replace. So we'll see if it solved the issue.