FJ Cruisers of Northern California

Auxiliary fuel tank

FYI for anyone interested:

- Don't try and make one on your own unless you are an accomplished fabricator. I've tried and failed. I'm sure it's possible but after I got my stuff together, I started thinking "I've got 17 gallons of fuel underneath me did I do this right?". Needless to say, it's not a good feeling.

- Man A Fre makes a good tank. It is made out of aluminum and I've spoken to a guy who totaled his FJ in a front end collision and the tank was fine. I'm not sure if I would take it on the rubicon but I wouldn't be surprised if someone has.

- There are other manufactures who have other aux. fuel systems out there but they are not "mass produced." However there are other manufactures who are working other systems and there are rumors that some are going through the CARB and crash tests which would make them 50 state legal. I guess we'll just have to wait and see when these get released and how much they'll cost.

I bought a used MAF tank and I had a modified filler neck and all other supplies to make it work. The electrical is done and I'm just waiting for some fittings to arrive and I'll have the tank installed. I've spent a lot of time and money on this and I would be happy to share what I know to anyone who's interested.

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Permalink Reply by pkelly72 on September 20, 2009 at 6:01pm

Is anyone interested in helping me install the tank on wednesday of this week? I live in Turlock which is south of modesto.

I'll give you my spare modified filler tube for your help (It's about $130). I ended up with two MAF filler tube's.

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Permalink Reply by Bz on September 20, 2009 at 7:39pm

Dude your timing sucks, I'd be down to help out but lots of us are headed to the Mts on weds. if you bring it up to the high sierra run I'd be happy to help =)

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Permalink Reply by pkelly72 on September 23, 2009 at 1:42pm

Done.

Getting the filler neck in/out was a pain. You need someone to help you get the tank in place also.

Pictures to follow soon.

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Permalink Reply by Swingshiftworker on October 14, 2009 at 7:39pm

I had MAF install their tank in my FJ over 1 1/2 years ago and took it on a 700+ mile of Death Valley last October.

Went from Lone Pine to Ridgecrest via Cerro Gordo, Lee Flat, Hunter Mt., Racetrack, Lippencott Trail, Saline Valley Hot Springs, Eureka Dunes, Stovepipe Wells, Mosaic & Cottonwood Canyon, Furnace Creek, Echo Canyon/Eye of the Needle/Inyo Mine, Amargosa Desert, Beatty, Titus Canyon, Warm Springs, Striped Butte, Mengel Pass, Barker Ranch (Mason's cabin), Goler Wash and Ballarat. It was a great trip!

Only one complete fill-up after around 500 miles at Furnace Creek. Two other fill-ups in Stovepipe and Beaty were only partial fill-ups of the main with the entire auxilliary tank still available in reserve.

The tank works great except for occasional check engine lights (apparently due to leaky seals) and extremely slow fill-ups due to the restrictive filler tube. Need to get down to Simi Valley to have the seals replaced.

Did you mod your own filler tube or use the one MAF supplied? There was a guy on the FJ Cruiser Forum (bbhog, I believe) who said that he had a fix for the restrictive filler tube problem, but I could never hook up with him.

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Permalink Reply by pkelly72 on October 15, 2009 at 6:33am

I used a MAF supplied filler tube but I actually had 2 to chose from. I had the old style (from a failed project $), which had no vent tube built into it and required you to cut into your stock system and the new style, which has the vent tube welded into the filler tube just below the plastic on the fill neck. This is now where the gas is vented. They must have changed their design. I haven't had a light go on yet.

The only issue I have is extremely slow fill ups. I'm glad to hear I'm not the only one. I am really happy with it.

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Permalink Reply by manoweb on February 19, 2011 at 5:34pm

So after all this time, what do you think of this system. It's still one of the most interesting mods that I am interested on...

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Permalink Reply by pkelly72 on February 19, 2011 at 6:06pm

That's a good question. I have basically installed and re-installed my tank about 3x. The more I mess with it, the better I get to know it.

There are essentially three different parts to the system:

1. Electrical - I think the wiring is straight forward and I have not experienced any problems.

2. The tank, fuel lines, and fuel pump - The tank is the biggest source of problems. If it's not sealed correctly you get 4 different codes. You then have to drop the tank and re-seal. This can be extremely difficult by yourself due to it's size and shape. I did replace a fuel line and a vent line. They looked like they were cracking and when I had it down I replaced them.

3. Modified fill tube - The fill tube can be difficult to get in and out but it really has been problem free.

I'm happy with it but it's a lot of money. I do use it more than any other mod though. They come up used once in a while and I wouldn't hesitate buying a used one.

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Permalink Reply by manoweb on February 19, 2011 at 7:49pm

I know it's a lot of money - too much actually - the problem's that all the other solutions are somewhat not desirable. Having 10+ gallons of fuel on the roofrack, having to climb up there, transfer the fuel... spills, etc...

So far I used two tanks that I kept inside the cargo area, but it's quite dangerous (at least as keeping them on the roof) and I do not want to use that solution anymore.

On the other hand, there is no way places like Death Valley or remote places in Nevada can be explored without at least ten more gallons, and 19 extra would be SO useful.

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Permalink Reply by gringo on February 19, 2011 at 6:11pm

I considered putting a 16gal fuel cell in a fabricated rack mount in the aft section of the roof rack. The steel rack mount as a permanent fixture with the cell removable or mountable with ratchet straps. It would be gravity fed, no plumbing into the existing oem fuel system which is highly illegal for on road use in Ca (OSHA and DOT standards).

After doing some more regulation research, I found that you cannot transport a fuel container larger than 5 gallons for highway use in Ca without a permit (up to 2500.00 fine). Since the fuel cell was not plumbed in, it would be considered in the transport category.

So I backed out of that project, I do have the new fuel cell if anyone is interested for any other application

http://www.summitracing.com/parts/JZP-250-016-NF/

while I was poking around the net, I found this which I though was pretty cool but it probably too big :=-

http://www.transferflow.com/refueling_tanks.html

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Permalink Reply by manoweb on February 19, 2011 at 7:54pm

Interesting - I do not like the idea to keep all that weight on top, but why nobody came out with a much cheaper plastic fuel cell instead of the metal ones?