FJ Cruiser spare fuel tank wanted

[flintsghost]

I'm looking for some way to add fuel capacity to my 2011 FJ Cruiser via a tank. Carrying cans is not helpful as the Allpro system doesn't work on late models with the factory installed back up camera...I already tried it and it doesn't work with the 2011. I don't have nor do I want a roof rack and carrying cans on a roof rack is a pain anyway. I'm not interested in the MAF 19 gallon spare tank because cost and installation aside it always blows codes once one gets past the 19 gallon spare tank and into your standard tank due to the amount of suction caused by the vacuum. MAF says they can't guarrantee that it won't blow codes and it's a 8 hour install after the roughly $1600 cost. Somewhere someone has a better idea. I'm dying to hear it. It must be available in the US and 10 gallons is about a minimum for auxillarys though more would be fine. Be happy to hear suggestions.

 

[ginericLC]

Buy a small fuel cell and plumb an electric pump to it and have it pump the fuel into your main tank.

 

[luk4mud]

My 12+- aux tank plumbed into my main does not trigger codes on my FJ80. If I fill both tanks, pump the aux into the main then run both pretty dry, there is alot of back pressure on the cap, but that is because I plumbed into the main using the vent. I imagine that I will go through lots of caps because of the pressure, but its worth it IMO. Aux tank + fuel line + Kragen fuel pump = good simple system. I have a dual filler neck too, but you can easily cut into the main filler line and skip the dual filler if you want.

Ironically, my aux tank is a used one from MAF, it was sitting on a shelf in the back, lonely and forgotten. Dual filler is from Specter, used, lonely and forgetten. rest of the stuff is from Kragen. I have maybe $400 into the whole system. I thought it would keep me form having to carry cans, now I carry them for friends.

 

[BIGGUY]

I saw an FJ with the backup camera that also had the All Pro stuff. The owner just made a small bracket and moved the camera out a little and it seemed to work fine. I don't remember where or who it was off hand though.

 

[cactusjk]

Can you better explain blows codes once one gets past the 19 gal aux tank?

I'm looking for some way to add fuel capacity to my 2011 FJ Cruiser via a tank. Carrying cans is not helpful as the Allpro system doesn't work on late models with the factory installed back up camera...I already tried it and it doesn't work with the 2011. I don't have nor do I want a roof rack and carrying cans on a roof rack is a pain anyway. I'm not interested in the MAF 19 gallon spare tank because cost and installation aside it always blows codes once one gets past the 19 gallon spare tank and into your standard tank due to the amount of suction caused by the vacuum. MAF says they can't guarrantee that it won't blow codes and it's a 8 hour install after the roughly $1600 cost. Somewhere someone has a better idea. I'm dying to hear it. It must be available in the US and 10 gallons is about a minimum for auxillarys though more would be fine. Be happy to hear suggestions.

 

[TangoBlue]

My 12+- aux tank plumbed into my main does not trigger codes on my FJ80. If I fill both tanks, pump the aux into the main then run both pretty dry, there is alot of back pressure on the cap, but that is because I plumbed into the main using the vent. I imagine that I will go through lots of caps because of the pressure, but its worth it IMO. Aux tank + fuel line + Kragen fuel pump = good simple system. I have a dual filler neck too, but you can easily cut into the main filler line and skip the dual filler if you want.

Ironically, my aux tank is a used one from MAF, it was sitting on a shelf in the back, lonely and forgotten. Dual filler is from Specter, used, lonely and forgetten. rest of the stuff is from Kragen. I have maybe $400 into the whole system. I thought it would keep me form having to carry cans, now I carry them for friends.

What vehicle and pictures please.

 

[flintsghost]

I saw an FJ with the backup camera that also had the All Pro stuff. The owner just made a small bracket and moved the camera out a little and it seemed to work fine. I don't remember where or who it was off hand though.

It was on FJ forum and the pictures were put up. But what you just said is not all they had to do. It can be done but the Allpro set up had to be modified also as did the spare tire mount. I discussed this with the owner through email. And I know who did it. But it's not possible witht he spare tire carrier that the 2011 comes with, even Allpro knows that, and they are working on it. I was involved with that thread.

 

[flintsghost]

Can you better explain blows codes once one gets past the 19 gal aux tank?

What apparently happens is that the MAF tank feeds directly into the regular tank which has the fuel pump built in and it is designed to pull a certain pressure and needs a vacuum pressure which is why your fuel filler cap seals the vacuum in when closed. The MAF tank is designed to constantly fill the main tank as the fuel is drawn out of the main tank by the fuel pump. Once the MAF tank gets empty the fuel pump has too much vacuum pulling pressure through the fuel pump and the codes start popping up on your indicators on the dash, because of the excess fuel pressure. You then need a scanner to eliminate the codes and reset everything once you refill the MAF tank. I called MAF about it. It may not be a problem with a 10-12 gallon tank but with their current designed 19 gallon tank it is a problem. Some owners don't care and others don't like it much. I think maybe it depends on whether you have the appropriate equipment to reset the code. The person I talked to about it has the equipment to reset the codes and he doesn't care. MAF themselves say that it "could" happen and if you are close they will try to help. But if not, nothing they can do. I prefer not to keep going through a problematic situation where the vehicle keeps sending me to the dealer to have the service codes reset. Does that make sense.

 

[cactusjk]

Sort of. You must manually transfer fuel from the Aux tank to the main tank using the Aux tank fuel pump. This is done only when you want to transfer fuel. I think you might be onto something with respect to why codes pop up but something in the explanation is missing. It would be good to know how to avoid codes long enough to get smog inspected once a year. Other than that you can easily reset the codes using a Scan Gauge.

What apparently happens is that the MAF tank feeds directly into the regular tank which has the fuel pump built in and it is designed to pull a certain pressure and needs a vacuum pressure which is why your fuel filler cap seals the vacuum in when closed. The MAF tank is designed to constantly fill the main tank as the fuel is drawn out of the main tank by the fuel pump. Once the MAF tank gets empty the fuel pump has too much vacuum pulling pressure through the fuel pump and the codes start popping up on your indicators on the dash, because of the excess fuel pressure. You then need a scanner to eliminate the codes and reset everything once you refill the MAF tank. I called MAF about it. It may not be a problem with a 10-12 gallon tank but with their current designed 19 gallon tank it is a problem. Some owners don't care and others don't like it much. I think maybe it depends on whether you have the appropriate equipment to reset the code. The person I talked to about it has the equipment to reset the codes and he doesn't care. MAF themselves say that it "could" happen and if you are close they will try to help. But if not, nothing they can do. I prefer not to keep going through a problematic situation where the vehicle keeps sending me to the dealer to have the service codes reset. Does that make sense.

 

[flintsghost]

Sort of. You must manually transfer fuel from the Aux tank to the main tank using the Aux tank fuel pump. This is done only when you want to transfer fuel. I think you might be onto something with respect to why codes pop up but something in the explanation is missing. It would be good to know how to avoid codes long enough to get smog inspected once a year. Other than that you can easily reset the codes using a Scan Gauge.

Based on what I got from talking with MAF and their information, you don't manual transfer the fuel. Their currently system does it automatically and you have no switch etc to change over or anyway to control the flow. Codes show up once the auxillary tank is empty and the other tank is being used. Exactly how much main tank use activates it I don't know. The earlier versions of the tank including the smaller versions mentioned in response may have a manual switchover but the 19 Gal version they sell now certainly doesn't. In fact if you don't want it the fuel gauge is only an optional extra and no mandatory. Since smaller tanks don't seem to spit out codes it may also have something to do with the sheer size of the 19 Gal. Another tank system mentioned on FJ Cruiser forum doesn't apparently have that problem and its either a 10 or 14 Gal variety. It's also a non commercial venture and not a readily available item.

 

[targa88]

Just an FYI ( results may differ).
I have been running the MAF tank for more than a year. No codes.

Not that I am a fervent supporter of MAF's technical support.

Did the install with a buddy. Most important issue is ensuring there is a proper seal on all the connectors and around the gasket of of the fuel sender and float.

The transfer is a manual process ( flip the switch to transfer from auxiliary to main tank).

Part of the potential secret is not to run the tank dry. I always fill up before the last quarter tank is used.

One of the better mods = piece of mind ( got tired of waiting for another alternative = Long runner, etc)
Have done thousands of miles on/offroad without a glitch or code
To Cactusjk points = scangauge will reset the codes = codes will have no impact on the operation of the vehicle

 

[flintsghost]

Targa88's install

It's interesting that yours has a manual switch to change from auxillary to main tank. When I talked to MAF by phone, they told me that the fill from aux tank to main was automatic and there was no switching back and forth. I was talking to their shop foreman and not to a tech support person or an order taking clerk. So I am surprised to hear that you can in fact switch back and forth. I don't know why I should be though. It makes sense that all you would need to do is install a switch so that power is cut to the auxillary fuel pump and that would require the vehicle to switch back to main tank. That would of course make a huge difference in the amount of vacuum you are drawing. I did however know, as you mentioned, that the codes don't affect the actual operation of the vehicle. If it's pulling codes when it goes for recert for emissions it will not pass as I understand it, in some states, basically because the main code that shows up is that the fuel evaporative recirculation system is not working properly. Where I am that shouldn't be a problem.

 

[TangoBlue]

That's not the way I interpreted Targa88. He said, "flip the switch to transfer from auxiliary to main tank," which I take to mean, flip the switch [to power the fuel pump] to transfer [fuel] from auxiliary [tank] to main tank. This is the most common approach to employing an auxiliary fuel tank from my research which ensures integrity of the fuel evap recirc system. My 2 cents...

 

[flintsghost]

That's not the way I interpreted Targa88. He said, "flip the switch to transfer from auxiliary to main tank," which I take to mean, flip the switch [to power the fuel pump] to transfer [fuel] from auxiliary [tank] to main tank. This is the most common approach to employing an auxiliary fuel tank from my research which ensures integrity of the fuel evap recirc system. My 2 cents...

Actually the most common method of utilizing two fuel tanks in the majority of vehicle with two tanks is to have a fuel pump that is between the tank and the engine and a electronically controlled switch that opens or closes a valve that changes which tank the fuel is coming from, and in a very few cases a manually operated valve. That is a system that has been used for many many years in multi tank vehicles. In Toyota's, the fuel pump is located in the fuel tank and so when one mounts a second tank, it must feed into the main tank in order to get the fuel to feed into the main fuel system. Having a second pump which is switch activated that feeds into the main tank is what he was talking about and what I was referring to. MAF led me to believe that their tank had a pump which was in the continuous feed mode even when empty. At least that's what I thought he was talking about. It's the only way that it could work on a Toyota unless someone engineers a tank with it's own fuel pump and also comes up with a splitter switch to select one or the other and to simultaneously stop the fuel pump in the tank that is not selected. I suppose that theoretically it is possible to do that but so far no one has. With the earliest dual tank technology, like chevrolet or ford trucks used it was not that hard because the fuel pump was mounted on the engine block and it was in the early versions at least mechanical and was driven off the crankshaft. I have replaced a lot of them. They usually had a diaphram problem in the mechanical pump if one installed large oversized tanks. The remedy at that time was to install a electrical fuel pump which had no problem. Because of current computer technology in Toyota's the use of a second fuel pump may cause more problems than it solves. Not being an electrical engineer or a computer person I can't say but can only speculate. However, in the earlier dual tank technology with both electrical and manual switching, been there, done that, got the T shirt and wore it out.

 

[TangoBlue]

Uh, okay, I give up - my brain hurts now. All I was saying is that for this modification of adding an auxiliary fuel tank it is common to use an additional fuel pump (external or internal), activated by a momentary switch in the cab, to pump fuel from an aux tank to the main tank, thus causing less problems, e.g., throwing a code. That's just from my web research for those who have successfully performed this modification, and myself who is about to. Any fuel cell can be used as long as it can be safely mounted, including other manufacturers.