1HZ Fuel Return Line - To Tank or ??

[1tontoy]

Can the 1HZ fuel return line be routed back into the supply, pre-filter, with a one-way fuel check valve? Anyone see any issues with this?

Other ideas or options besides running back into the tank?

 

[ForealBoreal]

Back to the tank.

Rotary pumps are a but more sensitive to air in the lines, heat and lubrication.
The fuel going through cools the pump and lubes it.

 

[roscoFJ73]

Why would you want to change it? The fuel is sent back to cool ,which is why it draws so much.
Heat kills them quick as the internals want to expand.

 

[1tontoy]

I don't currently have a return line to the tank.

Would plumbing it back into the main line before the huge filter, so that it is re-filtered, not cool the fuel down enough?
Would a one-way check valve work in this situation?

Why would you want to change it? The fuel is sent back to cool ,which is why it draws so much.
Heat kills them quick as the internals want to expand.

 

[roscoFJ73]

I don't currently have a return line to the tank.

?

Toyota began sending it back to the tank with the introduction of the rotary pumps in 1990 and have kept to that system ever since.
Ive also been told by diesel shops they are heat sensitive as a single plunger is doing the work that 6 pistons do in the inline pump.
The plunger and the bore that it moves around in have tolerances so fine, a swiss watch maker would be proud to work with it.
If it over heats,it expands and wears quickly.This in turn causes the pump to lose pressure and will in short time need a rebuild.

I would look at plumbing a return line to the tank,Im sure one could be braized on.

I cant see why your return to the filter wouldnt work ,except for the cooling issue.
Maybe you could add an inline oil cooler.

Its just that the current system works well and I cant see the reason to change it.

 

[1tontoy]

Thanks alot. I totally agree that the OEM system is the best to follow.

I guess I'm just seeing if anyone has done something a little different when there is no OEM return line (HJ47).

Maybe I can find another 40 series that has a return line with the same fuel tank...?

Or, run the return all the way back to the OEM water separator. That might give it enough time to mix and cool, there would be less "back pressure" fighting against the check valve, too

Its just that the current system works well and I cant see the reason to change it.

 

[roscoFJ73]

Maybe I can find another 40 series that has a return line with the same fuel tank...?

:

Im sure the FJ40 after a certain date had a return line because the fuel pump on those pumps similar amounts to the feed pump on a 1HZ.
When I did my 1HZ conversion to the FJ73 it had a return line and another for venting as well.