slow2v04

i have a 04 mustang gt..i bought the car bone stock and every now and then has a misfire.i would change coils and the car ran great for awhile until this misfire happened again.it always happens when i would nail it messing around..well i hadn't had the prob for awhile so i started modding.i know how a fully bolted and built 4.6 and I'm having major misfire issues in all 8 cylinders.i thought maybe when i installed the heads and cams it just needed to be tuned,well after getting tuned the misfire is still there.1-8 all misfire detected when pulling the codes.Ive changed plugs coils injectors and now starting to believe its a ecu problem...when the vehicle was tuned the ecu was not wanting to hold the tune.we tried the Diablo tuner the sct chip and finally after messing with it we got the sct xcal 3 to start a program on the car,but even then it was a pain because the car kept wanting to do its own thing so the fore leads me to believe further that its possible that the ecu is bad...need some advice

slow2v04

excuse me typos my niece is asleep and i have all the lights off.hahah

slow2v04

dam thanx for all the info............

KStromberg

Just a shot in the dark here buddy, speaking from personal experience. When you install a chip into your PCM, be sure ALL the silver solder mask from the factory that was applied to the J-port is removed down to the copper. You should see shiny copper on all the terminals both front and backside for the chip to make sufficient contact to work properly. Don't go too crazy as you don't want to make the contacts too thin, but copper showing on all terminals is a good thing.

I suppose it may be possible that you have a faulty cam position sensor?

__________________
-1992 Ford F-150 (winter truck)
-1998 Lincoln Mark VIII LSC (fun car)13.591@101.72mph