Changing from Subtank to main.

[Blatchy Lurker Find all posts View Profile Close Blatchy]

Hi, on a 95 series petrol will the fuel tanks automatically change from sub to main when the sub tank is empty. Ive been changing it over manually but saw somewhere that the 120 series does it auto.

[StormyKnight Advanced Member Find all posts View Profile Close StormyKnight]

I thought the 120....later version....

Runs from the main tank until its close to empty.
Turns on the 90L light in the fuel guage indicating that you have 90L to go
Then pumps the fuel into the main tank from the sub tank so that the guage now indicates the remaining fuel.

There is no manual switch to change over.

I guess they also don't have two filler nossels? Does it just go into the sub & then overflows into the main?

Cheers
Richard

[Guest Close Guest]

The 120 constantly circulates the fuel from one to the other via a venturi (jet) pump on the fuel pump (in tank). This stops fuel from going stale.

There is a couple threads that actually show how it works better, but I havent got time to search them out at this point.

Cheers.

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

Sub tank

It will definately need changing via the dash switch when empty otherwise like stated above it will run itself empty till the motor stops ops: . The only thing with the 95 series is when you first start the vehicle it will always start on the reserve tank (green light will come on) then once started will flick over to the main tank providing the switch is not switched on reserve in that case it will start and run on reserve till you flick back over to main.If the reserve is empty you will notice that a little bit of fuel is transfered automatically from the main to the reserve there fore showing slightly less fuel in main tank. It might take say a week for it to transfer roughly 1/8 of the main tank across to the reserve. This is also stated in the log books. When I first bought mine I thought the fuel economy was worse then it is cause the main tank seemed to be always dropping then realized the reserve had gone up off the empty mark. The 120 is a totally different set up. All works off the one guage. When all full the guage shows full, then when you use the whole of the main tank which will show half on the fuel guage it will then flick back to full, 90L light will come on then when guage drops right down to the empty mark your empty both tanks :shock: . Regards Steve

[DUZ TOY Lurker Find all posts View Profile Close DUZ TOY]

I always run off my sub tank first till it dies then switch to main till the light comes on then start thinking about refueling. I originally decided to do it this way so i didn't have to look at the orange light for 500km's. Is this bad or does it put enough fuel across for starting.

[K & M McF Senior Member Find all posts View Profile Close K & M McF]

Not a good idea. I used to run main to 1/4 and then change to sub-tank. A while back I got to 1/4 in main and decided to change to the sub-tank which had 1/1. Engine died. No matter what I did, I could not use the full sub-tank. Luckily, I was only in the Hunter Valley and had enough fuel to get to a petrol station. If in the outback, this could have been a big problem.

What had happened was the wires to the sub-tank had been ripped out by some 4WDriving we had done a few days earlier. I now only run main down to 1/2 and then switch to sub-tank. Then back to main once 1/2 reached. This is a lot safer than what I had previously been doing.

By the way, the problem with the sub-tank was easily repaired once I looked at it. Just a matter of reconnecting wires, but if it was a pump failure, bigger problems.

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

I use to flick between the two, doesnt really matter. I liked the set up better on the 90 as you could pick and choose where as my 120, bad luck. Say when I go to stockton beach I use to like the reserve tank full and by the time I drove from Sydney to Stockton I would try and work it out so that the main tank had just enough in it so the low fuel light wouldnt be on, this way I had minimal weight over the arse end so gave me that bit more clearance as well and I would just flick over to reserve while running around on beach then head home on the same tank. I dont think its a good idea to actually keep going till motor dies before changing over ?? This might not be doing the fuel pump any good, either way. Not sure how there set up in the tank but would imagine the pump would be imersed in its own little well of fuel but if your running it to the point of the motor starting to cough and splutter every time I imagine the pump would also be possibly getting hot from lack of fuel around it to cool down ?? Im only surmising here.........Cheers Steve

[DUZ TOY Lurker Find all posts View Profile Close DUZ TOY]

Thanks fella's
I didn't think of either of those points.

[Palmer Advanced Member Find all posts View Profile Close Palmer]

Thanks for the info guys, We had been worried about guage in our 120 when it switched at just under half on main tank, but now know why