100 Cruiser Sub Fuel tank X feeding into main

You are on your own at this stage...
Quite often i have tried puting fuel into my sub when i fill the main but it is chokkers.

That's how mine used to be too!!!!!!!

gazza414

We have a 02 V8 petrol and our sub tank has been "leaking" into the main tank since new.
Once i realised this was happening i complained to the tojo man prior to having the vehicle serviced and was told that it was the norm, i'm no mechanic and had to believe what i was told, going by the answer above it seems that it may be able to be rectified, would like to know how.
Cheers
Baz

Petrol or diesel?..

...and are parking it on a downhill slope for any duration, like overnight?

Gazza,I've got an 80s 4.5 petrol,as I understand it from the handbook,each time the ignition is activated a small amount of fuel is transferred from the sub to the main tank.If I use the car a lot ,but only short trips,stop start,I can easily pump a few litres over between fills.Maybe they use the same system on the 100s.Good luck Keith C

n the diesel version, a small amount of fuel is transferred into the sub tank when the engine is running from the pump return line. This is to help keep the system operational and also serves to remind the owner to use the sub tank from time to time.

Id hazard a guess and suggest that the fuel (Im picturing the setup) solenoid that swaps from one to other isnt switching completely, regardless of which its switched to.
In this case continuing to suck some from subtank as well as main even though its on main. All the fuel return is going to the proper place though and hence slowly transferring from subtank.

i've had my sub tank get half filled up once, when i was stopped on a steepish hill for a period of time whilst i set up to winch out where i was. beforehand the sub tank was practically empty, then afterwards it read half full. i thought this strange but sure enough i drove around on the sub tank for a few more days using the fuel that had transferred.
i posted a question about what happened on LCOOL forum as i thought it shouldn't be possible, but replies there said it was "normal" for it to happen.

I think you'll find that on all petrol Toyotas with twin tanks, there is a small amount of fuel transferred because there are two in-tank fuel pumps which should never be allowed to get dry.

The diesels do not do this because they don't have fuel pumps in the tanks.

Gazza, I suggest the leak may be via the tank breather lines. I assume that in 'normal operation' you have fuel solenoids on both the flow and return lines which are simultaneously actuated when you select to run off the sub tank?
Pressure can be equalised between the two tanks by operating the solenoid a few times whilst running.
Also check for a block in the breather line at the fuel filler cap.
Cheers, Tony.

thanks everyone for their input....I'll let you know how I get on
and if anyone else has some suggestions pls post.

thanks

Well my 2005TD Diesel doesnt do any of that I fill it to the top of the filler and run the main tank right down and the Sub is always full on the gauge.

My understanding is the two tanks are seperate and each feeds the engine but not each other.

A Patrol pumps the sub into the main tank but a Cruiser doesnt.


Mine has always been very slow to put the last 20litres into it Spits back and gurgles away. Have had the breathers checked but still does it.


Is the worst car I have ever had to fill the tanks on.