Dual factory tanks with fuel injection

[Rgallant]

I have a 1974 bronco with dual tanks. I want to keep them both but run fuel injection. Is this possible?

 

[spap]

Yes a lot more info will come but look at f250s with dual tanks and fuel injected diagrams
I'm on the same path
You can have a transfer pump from the aux tank go into the main tank easier way or set up two fuel injection pumps with a transfer switch pulling from tanks individually
Try the search will be a lot of info on it here

 

[rjrobin2002]

It's a ton of enginuity, but has been done.
If your not very skilled, it's more work than it's worth.

10 times faster to just get a large aftermarket rear tank already set up for EFI and just plumb one high pressure fuel line and pump with one return.

If you wanted to retain your axillary tank you could throw a cheap 12 volt transfer pump on it and "T" it into your EFI return line and have the ability to transfer it's 10 gallons to your rear tank.

 

[Rgallant]

I was already leaning towards the transfer pump plan. Seems the less troublesome path.
Thank you for your input.

 

[MarsChariot]

I have been running two tanks with the Pollack six-port valve for about a decade. I have no complaints. You just need to think about what you'er doing as you set it up. And use PTFE lines wherever you can't use hard lines. You will thank yourself 5 years later.

 

[spap]

My thought to have 2 fuel pumps is better just so your not stranded anywhere.
I'm very distrustful of current quality of almost everything being produced.
I have 23 gal tank with the pump inside the tank and was going to run the aux on an external frame mounted pump and tie into with the six port valve.
Anyway that's the plan. Haaaa

Or carry some fuel line and just siphon it out to fill a can.

 

[Broncobowsher]

Been done countless times. And there are so many different ways of doing it.

My preferred method, which is different than a lot of others...
Each tank gets a high pressure pump. Most pumps have a built in check valve, this keeps the fuel system primed for faster starts. So all you have to do is tie both pump outputs together, feed that into the filter and to the fuel injection. Which pump is on is what tank you are pulling from.
Return has a couple options. The simple is all to the main tank and the fuel system is a transfer pump via the return line. What I do is slightly more complex, but not really. The simple solenoid fuel tank selector. The basic low pressure carburated version. Plumb that backwards. Single in (instead of out) feeds a selected out (instead of in) to the tanks. Wire it so unpowered is main tank, powered is aux tank, and the power comes from the aux tank fuel pump power. So when the aux tank pump is powered, so is the selector solenoid and the return is divereted to the aux tank. Even simplier than the 6-port valve.

The fuel pump selector is based on the standard 5-pin auto relay that is energized by the other poll on the fuel tank selector valve (DPDT switch). Seamless in operation and as idiot proof as you can get on a 2-tank setup. With redundancy options if you ever have issues on the road/trail.

 

[Quick & Dirty]

For a few years Ford had low pressure pumps in the tanks going to an accumulator with the high pressure pump. Another option vs high pressure pumps in each tank with the valve to redirect the returns. There may be some benefit for offroad as the accumulator should stay full enough even when there is intermittent pickup from sloshing in the main tank.

 

[AZ73]

I run an aftermarket rear and aux tank with FI. There are many ways to do it, but I basically run a low pressure carter pump from the rear tank to the GM (Pollack) 6 port , then a Bosch High Pressure pump after the port to the FI.

http://products.pollakaftermarket.c...-valves/light-truck-6-port-motor-driven-valve

The issue is the switch is rated for a lower pressure than the FI needs. The Aux tank uses gravity feed to the port. I use a cross over wiring on the dash to control the port and I use 2 fuel gauges wired directly to the tank, but the Pollack switch will actually work with the single fuel gauge on the Bronco.

I followed the diagram in #9 this thread:

https://forum.ih8mud.com/threads/resolved-help-pollak-6-port-problem.826000/

But here's another ClassicBronco's thread on the topic:

https://classicbroncos.com/forums/showthread.php?t=312074

 

[Z Bronco]

I turned my front tank into what is basically a gas can. I use a frame mounted pump to take gas out of there to the return line to the main tank which has an EFI pump in the tank. I have a safety switch on the dash, so no accidental fills. Works great.

 

[MarsChariot]

Yes, you can wire the stock selector switch such that it not only selects the tank, it also selects the fuel level sender. So one flick of the switch and you change both fuel tank and fuel sender. All runs through the stock fuel gauge.
I have wiring if anyone is in need.

 

[blubuckaroo]

I'd be reluctant to go the transfer tank route.
That may be the cheapest option but it wouldn't work in my family.
Every car in the driveway is fair game. My three sons all used the Bronco, and are still welcome to drive it. That goes for their wives too. That's just how we roll.
So...all the cars need to be safe for everyone. I wouldn't call the fuel transfer system safe or multiple drivers.

 

[lars]

After 2 failed Pollak 6 port motorized valves (arguably in a 20 year span so not terrible service) I reverted to a manual arrangement last year. A 6 port manual valve, selector handle in the OEM location, dash switch simply selects tank sender as per OEM. Pump was and is a frame-mounted inline Walbro part with the usual pre and post filters.

I won't describe it as "best" and I made the installation yet more difficult by using AN-6 braided line and fittings everywhere, but once I got it in and plumbed, it's as simple as the original when in use.

Just another option...

 

[Broncobowsher]

As I stated before, and others have shown, there are countless ways of doing it.

 

[Steve83]

I tried several configurations on Frank's '75 5.0L, and eventually settled on the 6-port valve with 2 LP pumps on the frame feeding a HP pump on the frame to the injector rail. The factory dash switch (or a reasonable facsimile) was used to switch the valve/tanks & level senders simultaneously. It was his only vehicle for ~13 years, so it was very reliable. This shows most of the ways to wire the various configurations:

(click this text)

 

[Z Bronco]

The red switch is the safety switch, so no accidental fills into a full main tank.