Why does my 1994 Ford F150 4X4 5.8L truck hesitate and buck when accelerating?

What is your question?

My Ford starts fine, idles a little rough but not bad, has horrible gas miles, hesitates then starts to buck like it's not getting enough fuel to it when accelerating or driving up even the smallest of hills. I changed the spark plugs, wires, oil, distributor cap and rotor, fuel filter, fuel pump on the front gas tank, and the TPS sensor hoping any of them would fix the problem but nothing, it's still the same. I took it to O'Reily's for a diagnostic but the ECI would not scan. It started to shift rough a few days ago so I took it to a transmission shop for diagnostic but they said tranny is fine fuel system is fine and all sensors are fine. I am at a head scratching moment right now trying to figure this problem out any advise will be appreciated.