indycole
GOLD Star
I've chatted with my father and think I'm going to pick up a variable voltage power supply to see if I get the same behavior if I direct drive the fuel pump. I'm nervous what might happen if I put 12 volts to it for an extended period (recalling the warning from the fsm).
The power supply should be just fine for driving the pump, but I wouldn't drive the fuel pump ECU with it. It sounds like the fuel pump ECU is expecting a square wave. Maybe rent an oscilloscope to get more info about the waveform? Then, if needed, you could potentially drive that with a function generator.