Hey all. I have a 04 5.4 w/ a whipple supercharger. truck has 104k miles. Has a misfire in cyl 4 (p0304, p0316)
And spark knock..
I've changed the plugs, coil on cyl 4, fuel filter, and today the o2 sensor(pass side upper, bank 2??). ive ran tecron injector cleaner threw it, and always used Chevron 90 octane. (highest in Alaska)

The noise only happens when under load, or accelerating with more then half the throttle. doesn't happen when i slowly get up to speed.

Would anyone know what i could do next?

About to take it to the dealer to run a full diagnostic test on it...

Also, does not hesitate or bog. drives normal just with that noise

 

Depending on the boost of the Whipplecharger and the mileage on the truck, I would lean toward the air/fuel ratio being lean. It could be due the fuel pump or fuel pump driver module being weak or flowing insufficient fuel to satisfy the increase in air flow from the forced induction. You most likely will need to remap fuel strategy to cure the knock. That would require a reflash of the PCM or a programmer such as the SCT x3 with custom tunes written to account for the extra demand for fuel enrichment under boost. It may also be necessary for larger injectors, depending on boost level. Most likely the timing needs to be retarded more under boost as well. Custom tunes can address this. One thing for certain is this needs to be corrected ASAP. Platinum plugs DO NOT LIKE detonation. Spark knock will shatter the spark plug electrodes and damage the engine.

 

ya thanks. i have a diablo trinity i just bought. its 8 psi of boost, when i bought the truck, it didnt come with a programer.. Ford up here says they have a tune guy, and the closes shop for a dino or to get a tune done is 400 miles away... it didnt have this problem when i bought it, just started..

 

Also if it helps, when i pulled the plugs, they smelt of fuel like i soaked then in gas

 

If all 8 plugs smell of fuel, then you are probably getting enough fuel. But I would recommend highly getting the truck dialed in on the Dyno so you don't have any more problems. 400 miles away may be an inconvenience, but not near as much of an inconvenience as a toasted engine.

 

Ford is convinced they can tune the truck, but with what dino? i called Whipple inc. and they said Ford wont be able to do it. So im gonna have to do the drive.. $600 for the dino, 400 miles, at 10mpg..... SUCKIN!