EFI return line to Aux tank

[PDQ]

I have searched for the possibilities of running EFI and still keeping the Aux tank and found a few solutions, not counting using it as a transfer tank, but am still unsure of how or where you could route the return line into the aux tank? Or does it just return to the main tank in it's own return line with check valves etc, and just take your losses?

Thanks as always

 

[Broncobowsher]

If you have to have a return line on the aux tank, look for a '73 with the factory return line. If you can't find one take the sending unit out and solder in a return line.

 

[Timmy390]

I use the filler neck vent on the main tank for my return. You should be able to use the filler neck vent on the aux tank too. Might have to extend the rubber line just a bit.

Tim

 

[Jfryjfry]

There is a tank switching valve that is made for efi that has 6 ports - it switches both the supply and return lines for the two tanks.

That doesn’t answer your question of how to plumb the return but if you pull from the aux tank and return to the Main, your aux tank will be dry in short order.

 

[Broncobowsher]

It actually takes a lot longer than I expected to transfer the aux tank into the main tank via the return line.