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Using Aux Fuel Tank as On Board Jerry Can

RADO

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Sep 26, 2016
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138
Loc.
Phoenix
I'm planning a Rubicon run this September and would like to carry additional fuel for the trip. I have an auxiliary fuel tank lying around and thought it might be useful for additional gas. I converted the fuel system to EFI with a 23 gallon tank, which is why I can't use the original aux tank setup. I want to use the tank like a Jerry can, by filling the main fuel tank through one of it's vents with a frame mounted transfer pump.

Anybody else using the aux tank for this? If so, what type of pump did you use to transfer the fuel? Do I need to vent the aux tank? Any advice is appreciated.
 

Z Bronco

Bronco Guru
Joined
Mar 17, 2007
Messages
1,141
I am a day or two away from starting my bronco after an EFI conversion, so don't have an exact answer yet on how my setup will work. I turned my auxiliary tank into a Jerry can, its fuel line now feeds into the return line powered by a external Carter fuel pump mounted to the frame. Picture is from install, it is now wired up to a safety switch on the dash, so it doesn't accidentally get turned on with a full main tank. More pictures on my Adventure bronco thread.
IMG_1289.jpg
 

hankjr

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May 11, 2013
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1,761
Howdy. I’m in the process of doing essentially the same thing. I started trying to use an inline pump to transfer fuel but that was too much based on how I ran fuel lines and placed fuel filter and still have good real estate for exhaust.

I just bought a carter pump and that fits much better. I will make final plumbing install next week where I will tie into return line to get fuel into 23 gallon tank.

I added a second vent to the passenger side of the 23 gallon tank and ran a vent line up the top of frame rail to firewall to charcoal canister with can-p into intake. I was planning to link aux vent to 23 vent on drivers side. Might stick a check valve in vent line to prevent backflow from 23 gallon tank but only if necessary. Will for sure install check valve to prevent backflow through pump from return line.

I have dedicated relay to power this pump and will link into tank switch on dash to activate pump.

aa377d3053f731d9b85acefeb01bb9db.jpg


I can’t yet comment on how this will all work

Hank
 

sykanr0ng

Bronco Guru
Joined
Aug 11, 2014
Messages
5,363
A transfer pump is one way to do that, just make sure you never pump onto a full tank.

But there is no real reason that you can't have two gas tanks and EFI either, there are electric fuel valves rated to 65 psi continuous use made by Pollak.
Wire the valve and the pumps together so the tank the valve is open to is the only one pumping.

Complicated is when you are trying to set it up for three tanks.
 

spap

Bronco Guru
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Jan 2, 2010
Messages
2,606
That’s prob the best and good if you ever have a fuel pump failure
Is there a way to put a in tank pump in the aux tank. Has anyone done that
 

wsager

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Dec 3, 2014
Messages
335

Mitche11

Newbie
Joined
Jul 14, 2012
Messages
29
The other option is to pump the fuel from the aux tank up to a fitting in a high spot in the vent hose of the main tank. This may remove the necessity of a check valve, and allows any gasses in the line to vent out the normal tank vent. The fitting is available from BCBroncos.
8841d3237c76ae26e81d3cbfd5f1e1a1.png



Sent from my iPad using Tapatalk
 

sykanr0ng

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Aug 11, 2014
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That’s prob the best and good if you ever have a fuel pump failure
Is there a way to put a in tank pump in the aux tank. Has anyone done that

Here's an idea. But I'm not sure of the depth of the aux tank.
http://www.gearhead-efi.com/gm-ecm-pcm-conversion/in-tank-fuel-pump-conversion.html

GM had that style of pump in v8 pickups, but you would have to research if the pump will supply the flow and psi that you need.

Pretty sure the Explorer and Mustang in-tank pumps can be adjusted for depth in the same kind of way.
I know the aftermarket pumps are adjustable, since they are sold for so many different cars and trucks.
You may need a stand-off to keep the pump from rubbing the bottom of the floor.
 
OP
OP
RADO

RADO

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Sep 26, 2016
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Phoenix
The setups looks good with the carter pump!

A transfer pump is one way to do that, just make sure you never pump onto a full tank.

But there is no real reason that you can't have two gas tanks and EFI either, there are electric fuel valves rated to 65 psi continuous use made by Pollak.
Wire the valve and the pumps together so the tank the valve is open to is the only one pumping.

Complicated is when you are trying to set it up for three tanks.

I was just thinking of the simplest setup, but you have good point. I'll look into the Pollak valves to see if a valved set-up makes more sense. I already have a spare Bosch 69100 in my parts bin.
 

CA Monkey

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Dec 4, 2011
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Tracy
btw.... I have a 351w with mustang EFI. I did the con driving from auburn all the way to the gas station in tahoe on less than 16 gallons. Just an FYI.

I could use the extra tank like you guys are talking about more than most.
 

spap

Bronco Guru
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Jan 2, 2010
Messages
2,606
Isn’t aux tank come in from the side maybe just a pump on the frame rail would be easier
It would be cool also as a Jerry can if someone else needed gas, haaa it is a bomb on the side though
 

sykanr0ng

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Joined
Aug 11, 2014
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Isn’t aux tank come in from the side maybe just a pump on the frame rail would be easier
It would be cool also as a Jerry can if someone else needed gas, haaa it is a bomb on the side though

The danger is over exagerated, on that TV show they strapped a couple of quarter sticks* to the tank so that it would blow up.
*dynamite that is
 

Cortez

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Jan 29, 2009
Messages
1,202
I did the pollak 6 way valve with an inline Bosch pump....for two tanks this worked fine. Just a head scratcher on set up but worked well when I got it figured out.
 

blubuckaroo

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Jun 11, 2007
Messages
11,795
Loc.
Ridgefield WA
I'm planning a Rubicon run this September and would like to carry additional fuel for the trip. I have an auxiliary fuel tank lying around and thought it might be useful for additional gas. I converted the fuel system to EFI with a 23 gallon tank, which is why I can't use the original aux tank setup. I want to use the tank like a Jerry can, by filling the main fuel tank through one of it's vents with a frame mounted transfer pump.

Anybody else using the aux tank for this? If so, what type of pump did you use to transfer the fuel? Do I need to vent the aux tank? Any advice is appreciated.

Unless you want to install a separate injection pump, your filler tank idea is a good idea.
However, I would wire it so the pump couldn't be used with the engine running. That would practically eliminate the chance of accidental overfilling with the engine running.
 

Broncobowsher

Total hack
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Jun 4, 2002
Messages
35,713
With an external EFI pump, I just installed it after the original selector valve. I could select what tank I would pull fuel from, but all the fuel returned to the main tank. A running transfer pump. If you ignore the transfer and try to burn the pump out, the engine will stall.

After getting the 23 gallon tank I found the aux tank to be a pain to use and quit using it. Didn't use it enough and kept having to remember to use it so the fuel wouldn't go bad.
 

OsideDave

Sr. Member
Joined
Nov 18, 2006
Messages
882
I have done the Rubicon twice on the 23 gallon tank with a q-jet carb. Both trips I had plenty of fuel. Always nice to have spare fuel though
 

tatersalad

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Joined
Jan 17, 2009
Messages
1,067
I plumbed mine into the return line using a transfer pump. I have the pump set to come on when I use the selector switch. After running it that way on a few trips I realized that the efi pump was creating a vacuum effect and pulling the fuel into the main tank w/o me hitting the switch. I am currently planning on plumbing it through the stock valve or an electric valve to stop it from doing it.
 
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OP
RADO

RADO

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Sep 26, 2016
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Phoenix
Good info, I think I have a good starting point for this project. I started last weekend by leak testing my tank. I still need to decide the best option, jerry tank vs gas tank...

Good to know on the Rubicon, as I thought spare fuel would be a must. Still, extra fuel won't be a bad thing. I've been thinking about this aux tank since I almost ran out of fuel last year on Elephant Hill in Canyonlands. I left the trail on E and still had a 40 mile drive back to Moab. Luckily, I had more gas than my gauge showed because I forgot to calibrate the sending unit before installing it!! ;D
 

nvrstuk

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Just a Bronco driver for over 50 yrs!
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Jul 31, 2001
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PNW
You probably just want the capacity...because there's no way you'll need 23 gal of gas on the Con...Done it several times with many others and nobody was needing fuel.

That said, a separate pump like others ha e said mounted on the frame rail...

I used a separate electric pu.p decades ago to use as a jerry can for the farm. Flip a switch and fill up the mower, anything you needed... slick and very handy!
 

Z Bronco

Bronco Guru
Joined
Mar 17, 2007
Messages
1,141
Having driven my bronco across the country, the extra capacity is why I kept my auxiliary tank. Between the two tanks I hold 35 gallons of fuel, and when I tow the M416 trailer, it has a 5 gallon Jerry can on it. There has been a few times where I was down to just a gallon or two of fuel. The joys of wheeling and remote camping.
 
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