I have replaced the intank pre-pump, and the exterior fuel pump. Relaced the spade fuse and fuel relay. Volvo specialist has hooked my up to the diagnotic twice at $80 a pop, and they can not figure out what is wrong. Car still jerks during acceleration from 2000 rpm to 3000 rpm and back fires badly. What can I do?
Is there a reset button on the ECU? Should I replace the ECU? Could leaky seals on the fuel injectors be causing it? It jerks real bad. So bad that my body is jerked forward and backward while driving.

Just installed the new exterior pump last night. Should it be making noise while running? I hooked up the wires the first time, and the car would not start, but the pump would make an loud noise as though it wanted to work. Thinking that I had the wires crossed, I switched the wires and the car fired right up, but pump humms loudly as the car is running, and emmits a little bit of a burning smell. I felt the pump after driving for an hours. It is not hot, barely warm. (does it smell this way for a short time because it is new?
Should I check the wires at the pre-pump? perhaps they are crossed?