100 series Landcruiser fuel tank problems

Have you check to see if fuel cap breathers are not blocked that is suck on threaded section of cap and should be able to suck air in .

From Graham

When you park your car at night, turn the main tank on so it will start the next morning :)

Or
You main need to replace the valves between the two tanks.
If there is a valve on the return line, this would be the one to check first.

These would be located under the vehicle between the two tanks.

Also the fact that the fuel is being transfered overnight might also suggest a breather problem, because one tank must be at a higher pressure than the other, but this shouldn't be the case as both fillers are joined into one so they should be the same pressure in both tanks.

Perhaps also to verify that what you think is happening is actually happening, try just running on the main for a couple of tank fulls (with sub empty).
Then run on the sub (with the main empty) for a while.

This would be just a simple way of double checking whats happening without costing you any dollars.

Bit of a strange one

How many Ks has it done?

Another thought - what if the switch wasn't working and you thought you were driving around on the main, but you were still running on the sub or visa versa ?

I'd guess your fuel return solenoid is sticking.
I believe that you can crawl under the vehicle while someone switches between tanks (Ign on) and either hear or feel them click. Theres two of them - the return solenoid has the smaller hoses.

The vehicle has done 100,000 klm and you can hear the solinoids clicking when changing between tanks

Thank you Andrew,

The main solenoid costs $280.00 and the return costs $235.00
plus fitting costs thats why I'm trying to find out what the problem is


Thank you to those who have replied

Mal