White87GTA5spd

Let me start buy saying that I'm all outa money and I've got no more hair to pull out, so any help is welcome.
car spec: 87 gta 305 stock(as far as i know)
t-5(freshly rebult) new flywheel, clutch
3.45 rear
digital dash
catback, flowmaster
I'm getting close to saying to hell with this car! That would make every one i know happy but me. I love my gta!
The problem:
when driving at speeds below 3000 rpm it bucks andfeels
like its missing. also the digital speedo some times goes up when I rev the engine in neutral
Things I've tried:
picked up software to get real time reading from the ecm
tps is now set to proper voltage
o2 sensor is no longer lazy
plugs, wres, cap, rotor, new IAC
new MAF (that hurt the wallet)
checked the timming 6deg advance
new injectors

I'm at a loss as to why this is happening. I'm not a mechanic but i work on my own cars. I feel that I know more than most 25 year olds that I know. They all drive r i c e! If any onehas any ideas please send them my way.

deadbird

Have you checked the fuel pressure while revving the engine or driving ? I had a similar problem when I first got my 'bird, a test of the FP showed just w/o a load, it would sharply drop to 27psi with a blip of the throttle then return to 37psi just as fast.
Replacing the fuel pump was the cure. The previous owner had run the car out of gas 2-3 times which burns up the pump.
A really dirty fuel filter can cause a similar symptom.
With an analog multimeter, you can check the TPS sweep to make sure it's smooth. Bad contacts inside the TPS could also cause a similar problem.

White87GTA5spd

the fuel filter is new.
i tried testing the fuel pressure and it was 39psi. I didnt get to drive it with the gauge still attached. what the normal amout of drop in psi/rpm?

deadbird

It should raise.
The FP regulator is similar to an accelerator pump on a carb. When the throttle is pressed, the FP should raise supplying an extra amount of fuel.