What exactly do you mean by throttle response? Does the throttle not do anything? There is a lot of lag time? Or perhaps the car is lacking power?
Surely if the throttle does nothing it is more likely to be the throttle itself or the wiring / voltage supply.
Just by the way, it is not easy to change the fuel pump. After you get the carpet out of the way it is realitily easy to undo all the fuel lines paying attention to the colour codes. But getting the new one in and screwed down can be difficult.

