GQ Patrol 4.2 TB42E Fuel Pump Died

[aflman]

Hi all,
Any advice please on my 93 model GQ 4.2 TB42E dual fuel Patrol that now runs only on gas but not petrol. I did some troubleshooting and I no longer hear the fuel pump whine when I turn the ignition on. I checked the green fuel pump relay and the 15 amp fuse next to the battery in the engine under the black cover and all is good. As it is dual fuel and the petrol tank is no longer at the back where the floor hatch is, I don't want to drop the tank to check the pump yet, so hoping there is some other circuitry issue that might be the problem. The ignition still makes the clicking sound when turned but the fuel pump sound has gone completely. Anyone able to assist with my troubleshooting thanks?

[Turtle_au]

Does the dual fuel controller switch the fuel pump off when on gas? Maybe it's not switching it back on when changing over to petrol?

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[aflman]

Hi, thanks. If the switch is on gas or petrol I don't hear the fuel pump whine. It would make the sound in either mode in the past. Hope that makes sense.

[dom14]

It would depend on the way the switch is installed in your system.
If it's an auto switch that starts on petrol and run for couple of minutes before it switches to LPG, then it may not that simple
to diagnose it.
See if you can find the power line to the petrol pump and give it direct power to see whether the petrol pump works.

Yeah, definitely you wanna rule out other electrical issues, before dropping the tank to replace the pump.

[aflman]

It is an auto switch that starts on petrol but only momentarily and then switches to gas. You would always hear the pump as you start the engine in both modes. Circuitry is a bit confusing at present.

[garett]

commonly the petrol pump will still pump, be it recycling the fuel, and only the injectors stop working. (for some gas systems)
you might try to find the wires at a connection before the tank to check for power. or pull a fuel line off to see if it pumps. (catch the fuel).(disconnect the filter if it easy) if you have fuel a noid light on the injector to check for power pulses but more likely your dropping the tank.

[aflman]

I pulled the fuel line from the fuel filter and it isn't pumping. I just need to find the direct wiring to the tanks and put 12v there to see if the pump then works so I know it is something in the circuitry. Thank you garett.

[dom14]

I pulled the fuel line from the fuel filter and it isn't pumping. I just need to find the direct wiring to the tanks and put 12v there to see if the pump then works so I know it is something in the circuitry. Thank you garett.

Trace the wires from the tank and it should join a connector at the back of the vehicle behind the tank or bit further up towards the front of the vehicle from bottom.
I posted below links to my previous threads where I documented the wire connections from the tank. Wire colours may be different, but you get some idea.

http://www.nissanpatrol.com.au/forums/showthread.php?37565-Long-Range-Petrol-tank-access-issue

http://www.nissanpatrol.com.au/forums/showthread.php?38771-Petrol-pump-modification-redundancy-pump(RB30)

http://www.nissanpatrol.com.au/forums/showthread.php?38741-Long-range-tank-breather-line-versus-fill-line

[aflman]

Thanks dom14 will look into as soon as I get a chance. Cheers