Fuel injection on split tanks

[Andy]

Gentlemen, the CAV has two fully individual tanks and connectors are on the top. Usually (GTD, Ultima etc.) i just combine the two tanks on the bottom, suck from one and return into the same one. This works fine on all of my cars with EFI.

A switch is no option.

idea #1 was to use a fuel level sensor with a switch, that cuts of (via a relay) the corresponding pump. Con: in case one return line has better flow than the other one, the other tank will be flooded and fuel will leak at the expansion valve.

idea #2 was to run the two injector rails fully indiviually, two main pumps (which might make sense anyway, it's a 427), two catch tanks and two fuel pressure regulators. Con: lots of fuel lines and regulators ...

idea #3 is similar to #1: Using a fuel level sensor with a switch, running only on that tank until the switch in the sensor is activated and then switch to the other tank (using a solenoid). Con: lots parts and lines in the engine bay

Any other ideas?

Thanks
Andy

 

[Ian Clark]

There is no simple solution however a remote surge tank fed by a crossover from both fuel cells via a single lift pump will get you going...

If your car has the aluminum fuel tanks vs the bladder tanks the task will be simpler and safer. There are many threads dealing with the topic on the forum to read. This is not a Sunday afternoon job in the driveway...

Cheers Ian

 

[Dave Bilyk]

I made the choice, when I converted to EFI, of keeping it simple, so keeping the tanks separate. With carburettor, there was no return but the tanks already had a low pressure pump each, together with the fuel sensors they were switched over from the dashboard to change between left and right hand tanks. All I had to do when converting to EFI, was to get a solenoid valve with one fuel input and two (one to each tank) fuel outputs, the input from the hp regulator return. The solenoid is switched from the existing dashboard tank changeover switch, so that was as simple as I could make it.
Dave

 

[Bob]

Had a setup that worked well.
Was a two gallon tank placed just behind ps tank.

Both existing pumps feed into tank via float check valves.
High pressure submerged with built in adjustable pressure valve to feed fuel rails.
Return line back into small tank.
Pretty slick both tanks fed the same rate and had a little more fuel storage.

Have a good one.

 

[Bill Kearley]

I have the same concerns, I like number 2. Running one fuel gauge would be close enough.

 

[Ian Anderson]

I have the same system as Dave Bilyk . I used a pollack valve and a selector switch.

I did look into using a single tank to draw from and utilise the fuel level sensor to trigger a transfer pump to feed fuel from the second tank to the one you use as the main tank. I was going to use a fuel level sensor that had a low level warning light setting, and take power from this to switch a relay to power the transfer pump.

ian