rodneyg73

iTrader: (1)

Does anyone know which two wires to connect for the 12V fuel pump mod on a 2000 GS300.

99 GS3

iTrader: (14)

I believe what I've seen is usually a new direct power wire with a relay, so the old power feed to the pump becomes the trigger input to the relay.

Dscustoms

iTrader: (3)

Are you trying to take the fuel pump control away from the little factory fp module? Have you converted to a return system?

TonyN

iTrader: (1)

If the GS is anything like the MKIV Supra 2jz fuel system then there is no need, even for the MKIV supra it has been proven not to do a dam thing. All you will do is waste gas, the pump runs at a lower voltage for normal throttle, WOT the pump goes full bore when extra fuel is needed. Running full time 12v will not do anything in terms of power. I did this mod orginally to my Supra, nothing gained. Switched it back, if your boosted you will need a 2nd pump or more normally anyways and need to redo your relay. For normal GS3 you dont need this, for boosted ones you are in a different game anyways.

rodneyg73

iTrader: (1)

Yes I am and yes I converted to a return system.

rodneyg73

iTrader: (1)

I'm running two intank pumps, but I was told I need to do the 12v mod because running two pumps takes power away from each other.

TonyN

iTrader: (1)

Like I said if you are running two pump you want to redo your anyways. Bigger power cable, new relays, etc... my response was for a single factory pump, in your case go to Supraforums and look up pump relay and see how people do it, there should be a DIY somewhere on there.

99 GS3

iTrader: (14)

You may have worked through this already, but I was building my fuel system this past weekend and thought I would answer the specific question you were asking.

The GS Fuel Pump Controller (FPC) is behind the carpet in the trunk on the drivers side and has 6 wires going to it. Battery + and -, Fuel Pump + and -, and two small gauge ECU control wires DI and FPC.

Without saying what you should or should not do, what I think you are referring to is just connecting the Battery feed from the FPC and jump it to the Pump +. This does work and you would cut the Black/Red Battery + and the Blue/Red Pump + then just connect the two together. You could also do the same to the White/Black and Blue/Yellow wires for the Ground and then just disconnect the FPC completely.

This would be fine for the standard 12v mod on a single pump, which has good and bad opinions of doing this, so I won't comment either way.

But I will say the 25 amp fuse under the hood labeled EFI and the Black/Red wire coming from it to the trunk FPC are both too small for the amps that 2 pumps will pull. I would recommend coming up with a different power solution for the second pump. The 2 pumps should be on separate fuses as well.