racerjc

Im having detonation under light loads(up hill) while cruising. (New plugs new coils) It also starts to miss and shutter. If i let off and it comes out of converter lock up its better but will still do it just not as bad. If I stay in it detonation will stop and it will miss a little and almost run fine but feels down on power. If i floor it it doesn't detonate(I'm assuming because it needs more advance) but it does surge. My programmer has vcam PID's and fluctuates a lot. At idle it reads 0-1 and cruising around upper 40's to lower 50's under light load it will advance to single digits and that's usually when it starts its crap. So I'm wondering if I have bad VCT solenoids or maybe a vacuum leak in the Evap system but why no codes or CEL?

techrep

iTrader: (1)

Mileage ?? what brand plugs and COP's ?? have you checked FPDM and CAT's

racerjc

121k Motorcraft plugs. MSD coils. I have not checked FPDM or cats

redraiderford

Could the cats really cause those symptoms?

racerjc

Well I took it to the Ford house and they discovered 2 plugs were destroyed. I assumed it was from detonation but they figured it was a lean issue caused from the MSD coils and cold air. Anyway they replaced the plugs and it runs fine as of now. I guess I will put my stock air intake back on until www.powerhungryperformance.com gets my new tune written. I know the edge evo says not to run cold air with it because it designed for stock. But I have been running it with cold air for 2 years with no problems. The original plugs were fine when they were replaced last summer. So maybe the colad air with msd combined is not a good idea without a tune.

techrep

iTrader: (1)

I doubt the CAI had anything to do with it...but, you should have your tune installed to be efficient...