So I tore my car down and did a complete rebuild this winter. I put in a Supra Fuel pump and did the fuel pump rewire mod at the pump. It is the exact same mod I did on my previous 7. I'm not getting power when I turn the ignition on. I can jumper the pump at the relay and get the pump to come on, but I must not be getting a signal from the front of the car.

- The fuel pump will power on if I jumper the power wire to the pump positive wire.
- With all 4 wires hooked up to the bosch relay the pump doesn't power on.
- The pump won't power on if I jumper the the original power wire from the front of the car to the pump.

The car worked fine before I parked it and the pump works and start the car...curious if anyone else has had this issue or what to look for with the stock wiring harness.

Mark

 

I'm sure you have but I would check the fuses and just to clarify you're not receiving the indicator power from the front of the car to the relay? If not go back to where you spliced your indicator for the relay switch. Did you add an in-line fuse for the power supply if so have you check that fuse. I recommend taking a look at the "Dale Clark fuel pump rewire thread"

 

There is nothing wrong with the relay mod. The taste is with the grounding of 1T at the computer. The ground signal to the #10 fuel pump relay is not getting to the relay to pass power to the fuel pump (speed) relay and then to the pump.

I'm going to run a wire from the computer at 1T (L/B) to the fuse box to see if that will make it work. There is no continuity when I tested it.

Question is with the dual phase system and the relay mod, can I just run the signal wire to the relay at the pump and make it a single player base system. What are the secondary or tertiary effects? I'm running an aftermarket system with CJM rails, FIC injectors, and Fuel Lab FPR with no stock FPD....thoughts?