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- #21
In case anyone wants to look at the 200 Forum that I accidentally hijacked on this Topic.... There's quite a bit of overlap: "LRA aux tank and slight gas smell"
LRA Aux 24 Fuel Tank - How to Modify for 100s from 2006-2007.
- Thread starter porkandcorn
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GTV
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Good luck @porkandcorn please keep this thread updated!
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- #24
(UPDATE 05.14.22 - I HAVE NOT PURSUED THE OEM-ISOLATED SYSTEM BELOW, HOPING THAT MOVING THE VENT BUNGS ON THE DUAL FILLER NECK WILL RESOLVE MY ISSUES.) Here's my proposed "OEM-Isolated System", which I hope will solve the evap/vent issues, plus all the other issues that the Australians didn't work out for us Americans. This system will, I suspect, not meet US emissions regulations, due to the Aux tank vent directly to atmosphere, but I don't give a s*** after what I've been through. The Oregon DEQ can suck it. In my Version 2, I've added a 2nd OEM charcoal canister in line with the vent to atmosphere for the Aux tank to help with smell.
Please let me know if anyone has any ideas/improvements. We are the last hope for 2004-2007 100 Series owners who want this system and it's range.
Please let me know if anyone has any ideas/improvements. We are the last hope for 2004-2007 100 Series owners who want this system and it's range.
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- Thread starter
- #25
Updated my proposed schematic above to V.2, plus switched to electric ball valves instead of solenoids, so they can handle from 0-180 PSI, and reliably seal off the OEM system from the LRA system when the valves are in normally closed position.
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Two things:
First I think you will still have the same problems because the OEM fuel system gets overheated by the exhaust. And secondly if you vent straight to atmosphere then your aux tank will not be sealed so it will only create more fumes and evaporate even more the hotter and higher you get.
First I think you will still have the same problems because the OEM fuel system gets overheated by the exhaust. And secondly if you vent straight to atmosphere then your aux tank will not be sealed so it will only create more fumes and evaporate even more the hotter and higher you get.
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- #27
Thanks for the ideas and potential fail points. This is what I need from you guys.
My thought on boiling: I've only once had the fuel boiling, which was in Utah (known for having fuel that leads to boiling), and on top of that I was climbing approx. 6,000 ft. in about an hour on a very, very rough boulder-laden road. I don't do that a lot, and so will either avoid that kind of climb in Utah, or know the consequences. I've been all over Utah, multiple times, in every other kind of environment, and climbed to elevation quickly with crap roads in all the other Western states, and never had boiling once other than in Utah's Henry Mountains. All that said, I will do some strategic heat shielding near exhaust areas.
My thought on smell/evap from LRA tanik: You are correct. My thought is that the LRA tank will be empty, when I'm in daily driver mode. Secondarily, when I am overlanding, my thought is to place a 2nd charcoal canister, and just before the mushroom filter for the Aux tank. (The OEM system will keep it's charcoal canister as well.) This should capture some, if not all, of the smell and vapor. I can live with some smell, if it means that the isolated OEM system will be fool-proof. And can't deal with any more fouled large evap canisters on the OEM side. I could potentially put two of these little charcoal canisters in series on the Aux tank vent, if I still get smells with one. The LRA venting apparatus will be made field accessible, unlike the large canister which is buried up above the LRA tank.
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- Thread starter
- #28
(UPDATE 06.11.22 - DO NOT PLACE NEW BUNGS AS SHOWN IN THIS FIRST IMAGE - SEE POSTS #41/#42 FOR CORRECT LOCATION).
Also, here are the modifications I'm going to make to the LRA dual-fill neck, to make sure something as simple as filling the tanks at the gas station, is not letting liquid into the 2 vent bungs. I'll do this, and hopefully this will solve all my problems and I won't have to place the 2 electrical valves and re-route venting to isolate the OEM evap system.
1. The 200 Series fill neck has the bungs placed on the upper body where I show my proposed new locations, and there are less fill and vent issues with the 200 series. Frankly, I can't believe they let anyone sell this design - a toddler could see it would cause problems.
2. The OEM-tank-bound output of the dual fill neck is 1 3/8" OD, whereas the 100 Series factory line is 1 1/16" OD. This means you have to put a hose in a hose" to step down, and that causes turbulence when filling, which promotes backups, which promotes fouling of the vent bungs. I'm going to chop off 2" of the LRA neck to OEM (the dotted lines), and then weld on a custom-sized transition (Dixon pharma grade transition is perfect, if you cut it down on both sides to get to my dimensional specs shown). Yeah, expensive, but I can find anyone with a metal tube swager that works on tube under 1 1/2".
Also, here are the modifications I'm going to make to the LRA dual-fill neck, to make sure something as simple as filling the tanks at the gas station, is not letting liquid into the 2 vent bungs. I'll do this, and hopefully this will solve all my problems and I won't have to place the 2 electrical valves and re-route venting to isolate the OEM evap system.
1. The 200 Series fill neck has the bungs placed on the upper body where I show my proposed new locations, and there are less fill and vent issues with the 200 series. Frankly, I can't believe they let anyone sell this design - a toddler could see it would cause problems.
2. The OEM-tank-bound output of the dual fill neck is 1 3/8" OD, whereas the 100 Series factory line is 1 1/16" OD. This means you have to put a hose in a hose" to step down, and that causes turbulence when filling, which promotes backups, which promotes fouling of the vent bungs. I'm going to chop off 2" of the LRA neck to OEM (the dotted lines), and then weld on a custom-sized transition (Dixon pharma grade transition is perfect, if you cut it down on both sides to get to my dimensional specs shown). Yeah, expensive, but I can find anyone with a metal tube swager that works on tube under 1 1/2".
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Just sent this reply to @porkandcorn via PM but posting here also in case it’s helpful to others.
Sub tank is the term Toyota uses for the aux tank. I don’t know about the 100 series, my experience is with the 120 (gx470/ LC prado). If you look at parts diagrams (partsouq is a good source) for gasoline engine 100 series in either gulf corporation (aka Saudi Arabia) or Australian markets you can find a version that comes with a OEM sub tank. Here for example check out parts group 7751.
partsouq.com
I have no idea on a shop that can help. I think most would avoid the mod since it messes with the evap part of the emissions system there’s probably some liability in doing the work. My point in my post is I don’t think the charcoal canister can’t handle venting both tanks, I think the issue is with fuel getting into the charcoal canister plumbing. Filling is just one scenario where this can happen. It seems like the issues are often reported when driving mountain roads or off-roading, I don’t think the contributing factor is the altitude but rather being off camber, making a lot of turns, or driving up or down grades. Fuel ends up in the hose going to the charcoal canister, plugs up the canister to the point that the fuel tank can’t breath, at which time it starts building pressure and then starts pushing gas out of the charcoal canister’s vent to atmosphere which is located at the top of the filler neck. This is mistaken for fuel burping out of the filler.
I think with dual tanks where the sub/ aux tank fills the main, by flipping a switch with the LRA setup or with a siphon pump in the OEM setup, sometimes the main tank gets over full. The US main tank not having the proper return line back to the subtank from the main starts to pump fuel into the evap plumbing, and eventually into the charcoal canister.
I think the solution ultimately involves preventing fuel from getting into the evap plumbing - a dry charcoal canister breathes very freely and should have no issues venting two tanks.
Sub tank is the term Toyota uses for the aux tank. I don’t know about the 100 series, my experience is with the 120 (gx470/ LC prado). If you look at parts diagrams (partsouq is a good source) for gasoline engine 100 series in either gulf corporation (aka Saudi Arabia) or Australian markets you can find a version that comes with a OEM sub tank. Here for example check out parts group 7751.
Body/Interior | Toyota LAND CRUISER 100 UZJ100L-GCAEKV FZJ10#,HDJ100,HZJ105,UZJ100 Parts Catalogs | PartSouq
In our catalog of auto parts for Toyota, you will find quality LAND CRUISER 100 UZJ100L-GCAEKV FZJ10#,HDJ100,HZJ105,UZJ100 parts at reasonable prices. For a convenient search use the part number!
I have no idea on a shop that can help. I think most would avoid the mod since it messes with the evap part of the emissions system there’s probably some liability in doing the work. My point in my post is I don’t think the charcoal canister can’t handle venting both tanks, I think the issue is with fuel getting into the charcoal canister plumbing. Filling is just one scenario where this can happen. It seems like the issues are often reported when driving mountain roads or off-roading, I don’t think the contributing factor is the altitude but rather being off camber, making a lot of turns, or driving up or down grades. Fuel ends up in the hose going to the charcoal canister, plugs up the canister to the point that the fuel tank can’t breath, at which time it starts building pressure and then starts pushing gas out of the charcoal canister’s vent to atmosphere which is located at the top of the filler neck. This is mistaken for fuel burping out of the filler.
I think with dual tanks where the sub/ aux tank fills the main, by flipping a switch with the LRA setup or with a siphon pump in the OEM setup, sometimes the main tank gets over full. The US main tank not having the proper return line back to the subtank from the main starts to pump fuel into the evap plumbing, and eventually into the charcoal canister.
I think the solution ultimately involves preventing fuel from getting into the evap plumbing - a dry charcoal canister breathes very freely and should have no issues venting two tanks.
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the problem you will have with running a second charcoal canister is that since both tanks share the same filler you won’t be able to draw a vacuum on the main tank via the charcoal canister leak detection pump if you have an open circuit to atmosphere via the second charcoal canister hooked to the aux tank. You would have to isolate the two tanks from each other and have a sealed filler for each. If you can’t draw vacuum on the overall system you wil get a check engine light/ evap leak code.
Something I am experimenting with is running the vent line to the charcoal canister as high in elevation as possible, with a loop up near the gas cap.
the idea is to force transfer between the two tanks to use either the return line back to the sub, or worst case the common portion of the filler to transfer before it would pump fuel into the charcoal canister. This should also hopefully put the overflow level of this line higher than the fuel level line when the vehicle is off camber/ grade/ or pulling G from acceleration/ turning/ braking. A better setup would be to have the canister itself at the higher elevation, or even a catch can type setup to allow gas to burp through the liquid. I am not sure if this setup will be effective or not.
Another thing to check is that all of your plumbing doesn’t have low spots in it, I.e it is sloped to drain liquid back into one of the fuel tanks and not create a P trap which could result in vapor pressure burping liquid through the plumbing.
A final option if none of these work is to relocate the charcoal canister into the engine compartment, if there is room on the 100, that is what @grinchy did on his 200, and getting the canister to that higher elevation can only help.
I realize this may not apply with the differences between series but maybe it gives you some ideas…
the idea is to force transfer between the two tanks to use either the return line back to the sub, or worst case the common portion of the filler to transfer before it would pump fuel into the charcoal canister. This should also hopefully put the overflow level of this line higher than the fuel level line when the vehicle is off camber/ grade/ or pulling G from acceleration/ turning/ braking. A better setup would be to have the canister itself at the higher elevation, or even a catch can type setup to allow gas to burp through the liquid. I am not sure if this setup will be effective or not.
Another thing to check is that all of your plumbing doesn’t have low spots in it, I.e it is sloped to drain liquid back into one of the fuel tanks and not create a P trap which could result in vapor pressure burping liquid through the plumbing.
A final option if none of these work is to relocate the charcoal canister into the engine compartment, if there is room on the 100, that is what @grinchy did on his 200, and getting the canister to that higher elevation can only help.
I realize this may not apply with the differences between series but maybe it gives you some ideas…
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- #32
The off-camber idea is interesting, and on my first two installs, I would have become suspicious - however, after my third install, I only did city driving, and the vents became blocked, somewhere, as usually, by the second fill-up of the main tank, resulting in the OEM tank accepting only the lowest flow rate. This was the case in after all 3 installs.
100% - the evap plumbing is getting liquid fuel in it somehow, somewhere, and preventing that by whatever means is the ultimate solution. In order to know what works to solve the issues, or more likely issueS, is to resolve the suspected points of entry one by one. I'm starting with the filler neck design first. Then, I'll test and move on to the next suggestion - which are many from the responses to my original post! Thanks everyone. Still collecting the cream of the contributions here:
2006 LC w/ LRA Aux 24 - Fill, Venting, Fumes, Dripping & Over-Pressurization Issues - https://forum.ih8mud.com/threads/2006-lc-w-lra-aux-24-fill-venting-fumes-dripping-over-pressurization-issues.1276871/#post-14309379
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- #33
My half-baked idea for adding a 2nd, small charcoal canister, connected only at the end of the vent for the isolated LRA system, is that it would allow collection of some smell, without obstructing venting when filling the LRA tank.
Also, I want to make sure other readers are clear - in the OEM system, there is a larger EVAP CANISTER (located above the LRA tank and only accessible when pulling the LRA tank), and a smaller CHARCOAL CANISTER (re-located during the LRA install into the wheel well behind the plastic splash faring) and more easily reached
I have verified on my 3rd install, that the EVAP canister was completely full of fuel by my second fill of the system, resulting in fill issues. I'm unsure if the CHARCOAL canister has ever been fouled in my rig. I know if has in others, including 200 series - which usually occurs during top offs of the tank.
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- #34
Precisely, isolate the tanks. By using those two electric ball valves in my posts above, you can do this and keep the convenient dual filler neck. When that valves are closed off, the OEM fuel evap system is plumbed stock. Only when you want to fill the LRA, or pump from it, do you shut off the truck, open the valves, and fill or transfer. Close the valves, and back to an OEM system that can perform it's normal evaporative tasks without throwing codes. Those two connections are the only 2 connections with the OEM system, as I propose a 5/8" vent DIRECT TO ATMOSPHERE from the LRA tank, an no longer sharing the OEM evap system.
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- #35
I think we've all reach the point here where I have to pull my tank, and fit the new modified filler neck. That is step one. Run the system, see if I have fill/smell issues. If not, great the solution was more simple than we all thought. If not, fine, I'm in it to win it. Then I'll likely next look at EVAP line hose routing, to get it as high as possible. Test, again. Then I'll probably loose patience, and that's when I'd isolate the two systems from each other with the ball valves in the dual fill neck.
I have a date on April 12 to pull the tank, and by then I'll have my mods dual fill neck ready. I'll keep you all posted.
I have a date on April 12 to pull the tank, and by then I'll have my mods dual fill neck ready. I'll keep you all posted.
GTV
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LRA no longer offers anything for the bastard 06-07 100 series.
longrangeamerica.com
They're acknowledging a problem. Has anyone here been in contact with LRA? I hope they're taking care of their customers that are having issues by coming up with a solution.
Long Range Fuel Tanks from Long Range Automotive - Buy in America
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longrangeamerica.com
They're acknowledging a problem. Has anyone here been in contact with LRA? I hope they're taking care of their customers that are having issues by coming up with a solution.
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- #37
I'm doing my own R&D to define the issues with 2004-2007 LCs using LRA tanks. I've modified their dual filler neck, and am installing it next week. The hope is that by relocating the vent line bungs higher up on the filler neck body, fuel will not be able to enter and plug the vent lines. (Note the two plugged-off old vent bung locations.) Additionally, I've stepped down the filler neck factory tank output diameter to match the 1" factory filler line, to decrease turbulence when filling, further reducing the chances of vent fouling. I'm optimistic. Vent fouling is the primary issue for our LC production years running these LRA products, as I understand it. If this works, we may all be back in business. Rediculous that LRA is making an end-user complete their product development, but whatever. I'm a very persistent guy.
If you read up further into my posts, I was also having fuel escape out of my LRA system when my LRA Aux 24 was full, or nearly full. After 2 re-installers missed it (disappointing!), I found a 3" long separation at an LRA factory weld, that was causing both fuel leaking, and Toyota EVAP codes. My tank was flawed from the very beginning, at the first install a year ago, as it's leaked from the very start! That weld is getting repaired, and I'm having the tank lined for extra protection against future weld failures. I'm happy to have found it, as it was an obvious and easy solution to the leak issues.
I'll report back here after I've been through a few tanks fills with the modified dual-filler neck system.
Here's the original filler neck with new parts to be welded on, and the final modified product:
If you read up further into my posts, I was also having fuel escape out of my LRA system when my LRA Aux 24 was full, or nearly full. After 2 re-installers missed it (disappointing!), I found a 3" long separation at an LRA factory weld, that was causing both fuel leaking, and Toyota EVAP codes. My tank was flawed from the very beginning, at the first install a year ago, as it's leaked from the very start! That weld is getting repaired, and I'm having the tank lined for extra protection against future weld failures. I'm happy to have found it, as it was an obvious and easy solution to the leak issues.
I'll report back here after I've been through a few tanks fills with the modified dual-filler neck system.
Here's the original filler neck with new parts to be welded on, and the final modified product:
Fantastic Tech thread guys. 
Following along and learned some good stuff.
@Toyoland66 very helpful assessment of the Gen 2 evap system workings & weak points. @porkandcorn Nice work on tackling the filler neck solution. Its beyond me that LRA would offer an aftermarket component with the strict requirements fuel cell at a very premium price thats not compatible with your truck. Effectively causes more trouble than its meant defeat.
Following along and learned some good stuff.@Toyoland66 very helpful assessment of the Gen 2 evap system workings & weak points. @porkandcorn Nice work on tackling the filler neck solution. Its beyond me that LRA would offer an aftermarket component with the strict requirements fuel cell at a very premium price thats not compatible with your truck. Effectively causes more trouble than its meant defeat.
Good luck! And thanks for documenting this process.
Where did you source the tapered tubing? I looked for something similar and had a tough time finding it in smaller sizes.
