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Fuel Pump Not Getting Power

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Old 06-11-14, 08:54 AM   #1
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Default Fuel Pump Not Getting Power

I recently had issues with my car stalling/stuttering so I decided to do 12V fuel pump mod (bypass fuel pump ECU) and car ran like a champ. Then a month after that I had issues getting the car to start up but after multiple attempts the car started up and drove fine. But one morning I went to drive it and the car would crank over and over but no start. My first thought was that the old fuel pump died out since it was getting full 12V and was maybe on its last legs. So I bought a new fuel pump installed and still same issue. I did not hear the fuel pump turning on at all so I tried swapping the EFI relay and still nothing. So then I tried jumping FP and B+ then try starting and nada. Once more I still have not heard fuel pump turn on at any point. So then I tested with multimeter and I do not get any power to FP or +B at all. So then I tried checking power to the wires I crimped together for the 12V fuel pump mod (green and black/red wires) and still no power with key in ON position. I also made sure the main fuse box was getting sufficient power.

Sooooo I am stumped. Is there anything I can test out to see why I am not getting power to fuel pump? I'm not sure if I can test the actual power source of the EFI relay itself or does jumping the FP and B+ bypass the relay?

Thanks guys!
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Old 06-11-14, 09:09 AM   #2
Ali SC3
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I don;t think that jumping it bypasses the relay. likely you lost power to that whole part of the circuit. maybe a relay or a large fuse in the engine bay.

1995 Lexus SC300 5spd Na-T ( TT Ecu Mod + a few others)
2003 Lexus GX470 AWD ( Build in progress )
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Old 06-11-14, 04:54 PM   #3
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Idk of any other fuses that would impact the fuel pump.
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Old 06-11-14, 04:54 PM

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