Fuel transfer repair.

[Cuppa]

The time has come to get the fuel transfer problem which arose mid Old Telegraph track 2 years ago. A job left until we got home.

The transfer pump worked if I applied 12v to it direct. For some time the sub tank gauge has read zero regardless of how full it was.

I think the most likely issue is a failed fuel tank float/sender in the subtank, which in turn will not let the computerised sub tank arrangement work. Sub tank light remains lit all the time when ignition is on. (Yes I have tried disconnecting the battery several times).

Of course if the sub tank level sensor proves to be ok there could be an electrical/computer problem. If that is the case the best option seems like getting rid of that little piece of electrickery all together & getting a manual on off switch to operate the transfer pump.

As the sub tank is not registering anything it seems dropping the tank & checking the level sensor is probably the best first option (& hope that it fixes the fuel transfer issue).

Now the question: Mechanic or auto electrician? (Please don't suggest I do it myself - if I was physically able to I would, but I'm not).

[BrazilianY60]

I´d say a sparky is best fit for the job.

[mudski]

Yeah an auto sparky should be able to determine the cause on this I reckon.

[taslucas]

Hi cuppa, long time no read mate. I am no help at all because I have no idea how the system works but I want to follow this thread because I have no idea how the system works! Feel free to post any system diagrams here and keep us updated while you work through it. I would appreciate the info. Cheers

[Cuppa]

Hi cuppa, long time no read mate. I am no help at all because I have no idea how the system works but I want to follow this thread because I have no idea how the system works! Feel free to post any system diagrams here and keep us updated while you work through it. I would appreciate the info. Cheers

The 'system' where fuel can only be supplied direct to the motor from the main tank, which is situated right at the rear of the vehicle, & is controlled by rudimentary computerisation is the stupidest part of the Patrol's design. Admittedly the two horizontal oil filters in a hard to reach spot are stupid, but the fuel transfer system is king of stupid.
Whoever decided that being able to pump from either tank at will was not a good idea, or that putting the weight of the tank which must be used behind the rear axle made sense was a moron with no idea of good off road design. Hate to say it but Nissan should have employed the Toyota designer for the fuel transfer system.

I tried to work with the supposed computer diagnosis when on the OTT. Can't recall exactly the procedure now, something like Turn on ignition, press brake pedal 3 times, stick your finger in your ear & say 3 'hail nary's ......& then count the number of times a light flashes & refer to manual for what that means. All well & good but I got no light flashes & I'm pretty sure that I followed the instructions to the letter several times.

When we left home I had a sense that carrying a jiggler hose with us would be a wise idea, tested it to ensure I could get most of the sub tank contents with it, into jerries. Just as well or we might still be at Canal Creek!

[mudski]

Do you have to drop the tank on the utes Cuppa to access the sub tank sender? In the wagons there is an inspection hole in the floor. Which makes things easier for us. and if the sub tank gauge is not registering anything, I'd dare say the sender is kaput, and stopping the transfer pump from working.

[Cuppa]

Do you have to drop the tank on the utes Cuppa to access the sub tank sender? In the wagons there is an inspection hole in the floor. Which makes things easier for us. and if the sub tank gauge is not registering anything, I'd dare say the sender is kaput, and stopping the transfer pump from working.

Yep it's in the top & impossible to get to without dropping the tank. I hope what you are saying is correct - it'd be the easiest way to fix the issue. Do you (or anyone else ) know of a failed tank gauge causing the transfer pump to stop working? I think it's the most likely cause, especially as the sub tank gauge was fairly erratic for a while before it stopped registering altogether.

[taslucas]

Haha, I am much the wiser now, cheers

.......from under the great down under.

[mudski]

Yep it's in the top & impossible to get to without dropping the tank. I hope what you are saying is correct - it'd be the easiest way to fix the issue. Do you (or anyone else ) know of a failed tank gauge causing the transfer pump to stop working? I think it's the most likely cause, especially as the sub tank gauge was fairly erratic for a while before it stopped registering altogether.

I don't know of anyone personally but I do know thew sender unit is linked to the transfer pump for auto shut off when the tank is empty, so if the sender is not working this would be the first place I'd be looking at. The sender needs to be replaced anyway...

[Cuppa]

The sender needs to be replaced anyway...

My thinking exactly.