Power loss at 4300 rpm need help please
 

hey all
i have this dam problem that is driving me nuts i have been working on stangs for years and this is a first here is my problem

when i accelerate hard in 1st,2nd,3rd, i have plenty of power up till 4300 rpm at this point it seems like the clutch is slipping or the engine is dropping off some time because of knock but i don`t hear any. but it will not do it if i accelerate slowy like normal driving .i won`t have the problem it almost feels like hesitation but the power comes back on when i hit 5000 rpm`s. sometimes

i have done a bit of work on my motor but this is got me stumped
these are my engine mods
2002 pi heads and intake only run 93 octane
mac cai
autolight platinum plugs
holley laser shot wires
under drive pullies
accell coil packs
frpp headers with full flowmaster exhaust and high flow h-pipe with
cats

the clutch is stock and looks alright

please any help would be great if anybody has ever experianced this problem or knows of a fix.

what about that fuel pump.. is it aftermarket? Have you completely checked out the fuel system? If you remember I had power loass and replaced fuel pump and it turned it back into a beast.

i have been doing some testing and it only happens when the cxar is completely warmed up to operating temp. i`m beggining to think is a timeing issue the fuel system have been completely check. i`m gonna try to cool the car down some more with new coolant, lower stat, and better fan to see if it helps i want to get a tune done but the closet place to me is 100 miles away.

First thing I would do is put some copper plugs in there.

thanks for all the help it was the plugs i got a colder plug and better thermostate and it seems to have fixed it.car has more power now to feels like

a big thanks to juiced4.6 for the help