Dual tank setup with mechanical lift pump

[Enforced_Leo44]

Hi everyone,

My M1008 has had a dual tank setup installed in the past, not by me, and whoever did that also decided to scrap the mechanical lift pump and install 2 electric lift pump, judging by the looks of it those pumps don't really look high quality, but rather some junky inline cheap pumps.
Also the fuel tank selector valve doesn't look too bad, I think it's from a civvy squarebody, just a normal 2 input 1 output selector, so one return and one supply line for each, I think it's a ACDelco U7000 or something like that

I'd like to keep the dual tank setup but revert back to the original mechanical lift pump system, and here comes my question: all the mechanical lifts pumps that I see sold online only have one input and output, without a return line, which I guess would be necessary to feed back to the selector valve. Would I be fine if I just plug off the return line at the selector valve? Or should I change the selector?

Thanks in advance, any suggestion would be greatly appreciated!

 

[chevymike]

You need a selector valve with return lines (i.e. 6 port valve). This way the pressure and return lines go to the correct tank, when selected. The return line comes from the injector pump and goes to the input on the valve.

The fuel pump/lift pump only accepts one input and one output. The input comes from the output feed from the selector valve. Each tank output and return line goes between the tank and the valve.

Here is the factory electric selector valve https://www.amazon.com/ACDelco-U7000-Professional-Selector-Valve/dp/B0013FY5KW

If you want a mechanical selector valve, you need something like this https://buyamericanvalves.com/sk-1036-6-port-fuel-switching-valve/

 

[Enforced_Leo44]

You need a selector valve with return lines (i.e. 6 port valve). This way the pressure and return lines go to the correct tank, when selected. The return line comes from the injector pump and goes to the input on the valve.

The fuel pump/lift pump only accepts one input and one output. The input comes from the output feed from the selector valve. Each tank output and return line goes between the tank and the valve.

Here is the factory electric selector valve https://www.amazon.com/ACDelco-U7000-Professional-Selector-Valve/dp/B0013FY5KW

If you want a mechanical selector valve, you need something like this https://buyamericanvalves.com/sk-1036-6-port-fuel-switching-valve/

Alright now I feel stupid lol, I totally forgot about the return line at the IP, all makes sense now
That solves just about all the questions, thanks a lot

 

[Enforced_Leo44]

Well after a thorough inspection of the situation regarding reverting back to the original mechanical pump, I noticed that whoever swapped it for a electrical lift pump also scrapped and threw in the garbage all the hard line from the lift pump to the injection pump, and I can't seem to find a replacement nor a safe routing for a rubber fuel hose. So I guess I'm gonna stay with the electrical setup but still I'm gonna swap in a higher quality pump with the correct flow rate, does anybody have a suggestion for that?

 

[deank]

I did some looking in the -34P. Found this, seems you can make item 16 from steel tubing and item 14 if you are handy bending tubing and using a flaring tool.

 

[deank]

And, hillbilly wizard has one ready to go.

Steel Fuel Line

Hillbilly Wizard sells the hard-to-find parts you need to build your project vehicle!

www.hillbillywizard.com