My fuel pump is seening ~8v at idle, and it never changes whether the car goes into boost or not. I want to bypass my resistor relay. I don't care about the extra fuel, I want the pump to see 12v at all times.

I searched and found the wires to jump, but it must've been for a S5 because I have different colored wires.

The wires coming from my relay are blue, white, yellow, and red. The two wires going to the resistor are black.

Which wires do I need to jump? I would guess red and yellow as they are the thickest but want to make sure before I do it.

 

Red to yellow did the trick. 12v at the pump at all times now.

 

To keep a fuel pump Resistor and relay from pulling in and supplying only approx 9vdc, all you need to do is depin the green/red wire at the ECU or the fuel pump resitor and relay outfit. Then it supplys a full 12vdc all the time.

Your colors don't ring a bell.

 

It's a simple simple that's easy to diagnose and cheap to fix. The only thing that can go wrong is the relay, and that can be replaced with a generic automotive relay. Why not put in a little effort to do it right?

Those aren't stock colours. May somebody else's hacking is the reason it's not working.

 

Can a bad relay cause a low voltage to the fuel pump??

 

I guess if the contacts inside the relay are burnt it might. The relay pulls in when the ECU puts a ground on the relay. When it pulls in the voltage from the batt is sent to a resistor in the package and THAT resistor is what lowers the pumps voltage. Normally.

Step on the pedal to put a load on the engine and the ECU senses that thru the boost sensors output. Then the ECU in turn removes that ground mentioned above (green/red wire) and that relaxes the relay and now there is a path to the pump that bypasses the resistor in the package. Straight batt voltage now.

The ECU removes that gnd during start so the voltage will be full batt voltage. Once started the gnd is put back on the relay. Relay pulls in. Path to the pump is thru the resistor now. The straight path thru the relay contacts is open so the pump can't get full voltage........until a load is put on the engine.

 

i have just subscribed to this thanx man,