97 3.1 running rough

hi i have a 97 ga with the 3.1 172k running bad. when it warms up it hesitates pretty bad anywhere from taking off from a stop or trying to pass a car at 50. its getting about 70 miles to a half tank. ive changed the head gaskets, intake gaskets, cts, cat converter, oxygen sensor, coil pack, wires, plugs, fuel filter, injectors, crank sensor, and fuel pump. i cant figure out what is wrong with it, any help is appreciated. it runs a lot better when its cold but once it warms up it starts acting up.

i hooked my computer up to it and for the intake pressure at idle its around 8.5hg and when WOT its around 28. isn't that kinda backwards? i changed the map but no change.