Been there and done that. If I put the shaft of the pump in a drill, It will pump fuel to the moon just about. Hook the electric pump motor back up and it might squirt a a little fuel, but stops quickly. . Pull the electric motor from new pump and install in old pump, works perfect. Old motor in new pump, no worky.

Trust me, the motor is just tired. I'm saving the old pump in case something else I take apart has a motor small enough to fit the case. Both pump mechanisms feel the same, the new one slightly stiffer to turn than the old one.