WOT problems

Alright so i have been dealing with this problem for a while now and i have changed a ton of stuff and its still happening. When i accelerate normally there is no real problems, but there is a point in the throttle when the car just dies. If i give it 3/4 throttle it pulls real hard but the second i give it more than that....like any time i give it WOT....the car just dies and stops pulling hard. It pulls much harder at 3/4 throttle than it does at WOT!! wat the hell is going on here? i am out of ideas now. is there a WOT switch or anything like that? because its very wierd that the car only does this when i floor it? Please help!! thanks guys

Anyone? bump

just replaced the fuel filter when i took the car back out for the winter. It could be the TPS, do u think that could change the way the car performs when i floor it? The more i think about it...it really could be the TPS. How could i check to see if its good or bad? if it is bad, how much to replace it? what else could it possibly be? thanks for the replies guys! keep em comming