1997 Gmc Sierra Bogs down at half to full throttle whats the problem?

[Sebrina]

I have a 1997 GMC Sierra and I have replaced the throttle positioning sensor, the crank positioning sensor,plus, rotor, cap, wires and also the ECM, fuel filter air cleaner, ect....it starts and runs but when you push the gas peddle to half or full throttle it bogs down really bad...do you have any idea what the problem might be?
It happens while at park/neutral and while driving. Thank you all so much for you replies I really appreciate it!!!

 

[Tony R]

just had same type of problem on my GM chased all kinds of possibilites ....It was engine temp sensor , and connection ,engine bogged down because computer was sending very rich mixture of fuel ,which it does at a cold start every time until sensor says engine is now warm ....lean mixture out ... with this sensor not working computer never gets the warm signal

 

[Phil]

Weak fuel pump.
It cant supply enough fuel to the engine at the higher engine speeds.