80 Series DIESEL Auxialiary Fuel Tank Probs

[highlift80]

Hey guys any one had any experience with this one. I was driving from Cobar to Melbourne last week started to get down towards empty on the main tank switched over to SUB the green light came on at switch as if I was switched over to SUB tank but the fuel guage for Main tank kept going down and and Sub tank guage never moved and its chockas with LIQUID GOLD that I can't use at the moment, any ideas where to start looking with this one.

[Emo]

Is it petrol or diesel? They have different systems.

[highlift80]

Its a diesel, I know on the petrol models the sub won't switch over until the main gets down to a certain level, diesels are supposed to switch over any time you push that button , so somethings a miss, todays my first day off in a few weeks so I'm checking fuses ,wiring, plugs etc see what i can find . I came down from Longreach to Cobar switcing on the Sub as required no probs did the switch over near Jerilderie and it stayed over on the Main tank..,

[Emo]

Its a diesel, I know on the petrol models the sub won't switch over until the main gets down to a certain level, diesels are supposed to switch over any time you push that button , so somethings a miss, todays my first day off in a few weeks so I'm checking fuses ,wiring, plugs etc see what i can find . I came down from Longreach to Cobar switcing on the Sub as required no probs did the switch over near Jerilderie and it stayed over on the Main tank..,

On the petrol, the subtank pumps into the main tank. If there is any room in the main tank, it will pump until full. I'd be checking fuses and wiring. As you say, the diesel swaps between tanks so something is wrong with the switching process.

[sniper]

With the diesel it pumps it directly out of the sub to the motor(well mine does). No ideas what would cause this unless there is a fuse blown, loose wire or the pump shit itself.

[dow50r]

Get a friend under the car and above therear diff is the solenoids and valves, check they are clicling when sub is turned on and off, check fior broken wires from sticks.etc, check fuse...if all seems quiet
Andrew

[BEU77y]

I've got the same problem....
I have in the past removed the two solenoid valves and cleaned them out... fixed the problem for a few years.
The only problem with removing the valves is the idiot engineers turned what is effectively removing 4 x 6mm nuts, into 4 hours of fuel running down into your armpits and swearing. It's not a fun job.

The main cause is the gradual build up of scum in the tanks. It gets stuck in the valves, and hey presto, they stop working. I've also heard that there are a few strainers in the tanks that gum up... but you have to remove the tanks to clean them. I've heard that these can actually affect the engine performance.

You can remove the hoses and blow air through the valves to clean them out. You have to turn the key on to get them to switch.
Some of the hoses will run fuel when not connected, so be ready to plug them.

I've asked my friendly Toyota spares bloke... who I'm on a first name basis with... and it's about $500 for two new valves...

I've tried teeing the lines together... removing the valves from the system, but the fuel just runs from the sub to the main, and then you get air... and the car stops with a cough and a splutter. Not good.

Try blowing the valves out

Have fun

[highlift80]

Thanx for the info I consulted the ol Gregorys and read up about the Solanoid valves and had a look at em saw what you meant about those little nuts and diesel runing down your arm when you disconect the hoses what a mongrel of a job. I will try giving em a blow out with the air gun I checked em they have power going to them so they may just be GUNGED up with crap, $500 for those valves geez they don't mind stinging ya do they.. Ohh and I will wear saftey glasses next time I go under might keep some of the hard baked red dirt from falling in my eyes again.
damn I hate that..

[BEU77y]

Go to your local carlovers and spend $5-$6 cleaning underneath before you start - or try goggles. I wear glasses anyway and still get crap in my eyes.