sti.dean

The car is a 2002 sti with a syvecs ecu. Is it possible and safe to bypass the fuel pump controller by bridging terminals on the fuel pump controller conector block so the pump will get a constant 12v supply. If so which terminals should be joined together

i am having a issue where relative fuel pressure is dropping as boost rises, it loosing around 5psi by 1.8bar of boost.The pump is a 340lph, the reg is ok and the wiring is fine. Looking at the calibration on the ecu it looks like its only turning the pump on and not using pwm controll, so i am guessing the pump controller is only running at default output probally 66% because the ecu is not telling it to go to 100%. I am just looking for a solution that doesnt involve hacking my wiring loom. If it works I'll get the pwm controll set up when i change something else and require another remap.
Thankyou in advance for any help

Don Clark

sti.dean

hi Don
Thankyou for posting the wiring diagram, unfortunately i dont fully understand what I'm looking at, if it involves using spanners i can fix it but I'm totaly lost with wiring. Do the letters refer to wire colours BW being black/white, BY black yellow if so they dont match the colours on my connector block 6 and 7 are the other way round. Which terminals do i need to bridge together on the connector block and is it a safe way of doing it.
Thanks
Dean

Don Clark

The above diagram is for the MY01/02 UK/European Impreza WRX and 02 STI which according to the manuals remained the same.
Is it a UK car? If JDM may account for the difference.
On the diagram 12v power is supplied to pin 10 (BW - black/white wire) from the fuel pump relay
Power to/from the pump are pins 6 and 7 (BW and (BY - black/yellow) wires)
Earth is taken from pin 5 (black wire)
To bypass the controller, you need to connect the live feed (pin10) to the +ve feed to the pump (either pin6 or 7) and then connect the -ve (remaining pin6 or 7) to the earth connection (pin5)

At a guess I would assume using BW wire for the +ve feed to the controller would also be the +ve output feed to the pump making BY wire the -ve return.