My truck has a GMC 270 cubic inch motor. When I accelerate above a normal amount it seems to cough and stumble. I let off the pedal and it catches up. When going up hill and trying to keep up speed it will also cough, doing the same thing. I let off the pedal a little and it runs ok.
I feel the fuel pump is not supplying sufficent fuel to the motor.
What say ye motor Gurus?