Wiring fuel pump and gauge

[65 Cobra Dude]

Folks,

How did you wire the fuel pump and gauge? I see there are 2 fuel senders, did you just short out the sub sender and wire the sender in the tank to the main sender wires if that makes sense. For the pump, just break out the wires from the connector and go to the pump? I am using the Boyd tank if that makes a difference.

Thanks,

Henry

[65 Cobra Dude]

Anybody know how to wire the fuel gauge? The pump is working. I have shorted through the fuel sub level sensor and to the fuel sensor and it always reads full tank. Anyone figure this out? It's an 04 Wrx donor.

Thx,

Henry

[RM1SepEx]

I remember someone else did the Boyd and they said something like the sender was wired backwards...

[metalmaker12]

I wired the fuel pump and sender pre fuel pump harness. If you notice the fuel pump and sender have a separate harness. Just wire off the plug that harness goes to. Ken Gilbert impreza Manuel's under engine diagrams will have what I am referring to.

Fuel pump: BOr+/ BW-

Sending unit ( on Boyd you have to reverse the float on the unit so it reads correctly) BR+/ BrW-
Technical you don't need the BrW - because you can just ground to frame and it works also.

[longislandwrx]

so you didn't use the fuel pump harness? how is it running with static fuel pressure?

[AZPete]

I need to keep the Fuel Pump Module, right? Thanks for the wiring info above.

[iWire]

Yes, you really need to keep the Fuel Pump Controller (FPC). It serves a couple purposes on the turbo applications. First it has 3 settings so that the pump works a low duty, mid, and high depending on how much you need. This saves fuel, and increases longevity of the pump itself.

More importantly, since the ECU controls the fuel pump through the FPC, it will shut it off in case of emergency (IE a crash). If you hard wire the pump without the ECU having the ability to turn it off, you could be in a lot worse trouble in case of an accident.

[Goldwing]

The 2 fuel level senders are wired in series each having about a 0 to 45-ish ohm range. We use one 0 to 90 ohm sender in the 818. As such, you have to change the wiring a little. In the pic, grab the BW wire from the fuel pump connector and the BrW wire from the sub fuel level connector, leaving out the L wire.
image.jpg
Finally, on the Boyd tank, the float comes reversed such that the "FULL" and "EMPTY" readings are reversed. It's a mechanical swap, and easy. Loosen the set screw on the float arm, slide it out, then reinsert from the other side, retighten. You then have to loosen where the whole assembly attaches to the mountin plate so you can rotate it 180 degrees to point the float back towards the tank.
image.jpg
Check the resistance before swapping. It should read near 90 ohms when empty. If it is near 0 ohms, perform the swap.

[Goldwing]

Since we're on the topic of the fuel pump harness, has anyone incorporated the fuel temp sensor anywhere? Can we just delete it? Or do we use a resistor to 'set' a value? What have you guys done? Pins 5 & 6 on R58 in the pic (from an '07 diagram BTW).
image.jpg

EDIT: I'm also a Boyd tank user, there seems to be no allowance for the temp sensor. I'm just trying to cross the correct T's so to speak.

[AZPete]

Bringing Goldwing's question back to top. I've got code PO183 - fuel temperature sensor A circuit high output
Anyone know what to do with the wires there?

Also, I've got code P1400 - fuel tank pressure control solenoid circuit low input
So, I apparently didn't wire the fuel harness right.

[philly15]

Bringing Goldwing's question back to top. I've got code PO183 - fuel temperature sensor A circuit high output
Anyone know what to do with the wires there?

Also, I've got code P1400 - fuel tank pressure control solenoid circuit low input
So, I apparently didn't wire the fuel harness right.

in the later year subarus they had both fuel temp and tank pressure sensors in the tank. im assuming you don't have either of these sensors in use, you can turn the code off manually via open source tuning, that's what im doing, since I don't want to put the sensors in.