2004 F-150 engine Problem

[electricdude12]

I took my F150 to the store on Thursday and everything was fine. I was driving and the truck started acting up. After a bit it went away only to return 5 min later. I shut the truck off an would not start again. After some investigating I found the #4 plug smashed in the head. I replaced he plug and It happened again and would not start. Do you know if anyone else had this problem?? The truck has 65,000 easy miles and always maintained
Possible causes???????

 

[Soniazy57]

I had similar problems on a '00. Cure was replacement of COP on the cylinder that was missing. While trying to find the problem I learned a lot however, sometimes the spring that extends from the COP to the plug has a bad connection at the output terminal. Just a little corrosion that can be hard to find. Actually the COP I took off was fine except for the corrosion.
Also, check your injector on that cylinder. Easiest way is to hold a wooden or metal dowel on the body of the injector while the engine is idling... you should be able to hear it clicking as it cycles, if not its bad.