That's usually the culprit, or aftermarket coil packs, stockers are the better ones to use

 

you didnt set the plugs gap tight enough. with 15lbs boost your probably running either a 6lb lower or 8 so set the gap at .34 using NGK TR6 plugs. make sure im u run 93 all the time, but im sure you know that.

most important things with these truck is the tune. make sure you have a quality tune and at WOT make sure overdrive is off.

 

What this guy said^^^^.. BUt I would put new set of tr6s and gap them like at .32. Make sure you give them a good snug on the plugs.. I run my plugs at .32 fro years now and never had a problem... May b some specs on the truck will help us out alot more to figuare out your problem.. GL jose

 

.32 is to tight for his mods but wont hurt anything. i run 22lbs boost on 18* and mine are gapped at .30 on c16 race gas. on street i run 17lbs 93 pump

 

hell i had to run .028 on 8-9psi. but my compression is 9.2:1 in my 4.6

 

i guess all are different my CR is 9:1 and plugs gapped at .30 running 22lbs boost

 

yeah i use to have coil packs and wires, but i bought the COP conversion harness, so i should be able to open my gap up a bit more

 

He is running almost double the boost. Im sure he will b fine. Couple of my buddys only had pullies and also ran .32 gap.. Non of us have had any problems..
Any update on this??

 

Check your gap, and it also sounds like a bad COP.

 

i had spark blow out on a f150 @12#s at 5k had to go down from .035 to .030 this on a 4.6 to now a 5.0 and at 9-1 comp.