Update new info: My servvice engine light has now come on. Codes form autozone are,
PO316-Misfire within 1st 1000 rpm.
PO302-Cylinder #2 Misfire Detected
PO455-Evaporative Emission Control System Leak Detected. (I did replace the gas cap two weeks ago after leaving it at the gas station)
Any help here Im thinking coil pack, I looked at night & can see no arcing? or does it go dead. The backfiring is my reasoning of the coil? Help!!

2002 4.2 80,000 miles, new plugs & wires, sprayed water in dark on coil pack & seen no arcing of cracks. Cleaned out throttle body. No service engine light. Have a miss with popping backfire sound. It only happens on when i take off then it smooths out? (Sounds like the old style distributer when it had a crack). I did fill up with gas right before this started, could water in gas have this symtom? Where should I look next? Thanks, Ed

 

Cracked plug,maybe? Bad plug wire? Did you use dielectric grease in the plug boots?

 

I had the missing popping before I changed out the plugs & wires. I changed out the out the wires and plugs after reading several posts that seemed to match my problem. The engine idles smooth, when I accelerate it pops & misses a few seconds until i get some speed?

 

With my second fill up of gas the problem is gone. Runs great! I reset the computer. I had some codes listed in a earlier post, figured it was the gas after i changed out the plugs & wires & still had the miss.
Until Today...Have lots of snow in drive, started it up to warm up. Plowed my drive, when I went to move my truck it was missing bad! Now its not just a miss when i give it the gas, but a steady miss...my ideas....
Clogged injector? Bad coil?.. any ideas,. Thanks Ed

 

The coil was bad.. It had a crack on the bottom of the case. Edal