LRA Aux 24 Fuel Tank - How to Modify for 100s from 2006-2007. (1 Viewer)

[porkandcorn]

(UPDATE 03.09.23 - THE LRA AUX 24 CAN BE MADE TO WORK FOR 04-07 100 SERIES, BY MAKING MODIFICATIONS TO THE SHIPPED FILLER NECK & TANK, ADDING TWO ELECTRIC BALL VAVLES TO ISOLATE THE LRA FROM THE FACTORY TANK/EVAP SYSTEM, AND FINALLY ADDING A MARINE-STYLE SNORKEL VENT FOR THE SYSTEM. SKIP TO POST #24 FOR THE BEGINNING OF THE MODIFICATION INSTRUCTIONS.

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(UPDATE 05.14.22 - LEAKS, FUEL SMELLS, AND EVAP CODE ISSUES RESOLVED. CRACK IN FACTORY WELD. SEE POST #44)

Here's my story/nightmare with my 2006 LC and an LRA 24Aux:

My LRA (Long Range Automotive) Aux 24, installed in July of 2021, has been plagued with issues, including - filling and venting issues, major fuel smells, substantial fuel leaking, EVAP error codes, and very dangerous fuel system over-pressurization at off-road elevation gain. The install was done in Oregon by Long Range America's (an LRA product distributor, not related to LRA) most highly-recommended shop. After issues developed, the LRA tank was pulled, re-asssessed, and re-installed by that same shop. Couple weeks later, after filling venting issues had returned, when climbing a rough pass in Utah's Henry Mountains, we pulled over at the summit to realized that hot vapor was blasting out of the gas door. It took 30 minutes to carefully depressurize the system. This had never happened in MANY rough mountain summits prior to the LRA tank install. You could hear the metal of the fuel tanks returning to their original size after expansion! Had something ruptured, me, my wife and my cat would have exploded in a 50 gallon hot gas bomb. That was not a good day for me an my Aux 24.

Obviously questioning the first install and second re-install, I took the truck to a trusted Toyota-certified/LC specialist overland builder (who has installed many, many LRA systems) to assess the those first two installs, troubleshoot, and try again. Same issues developed after a tank of fuel!!!! I was told by this Toyota mechanic that there was a redesign of the LC evap/fuel system in either 2005 or 2006, that could be making this otherwise reliable LRA product and system rather painful for owners of those production years of 100 series cruisers.

The distributor, Long Range America (LRAM), has done their best to help me find solutions, but they are also frustrated and at a loss of what to do for these 100 series issues tormenting some, but not all, owners. All the typical install mistakes that cause problems have been addressed: replaced lines and connections with highest quality materials, raised and improved 5/8" vent/filters, insured no kinks in lines, attempted resolving mis-matched diameters of 1 3/8" LRA output to 1" OEM fuel line, turned upward the 1/4" vent bungs on the fill neck to limit fouling from the incoming LR-tank fill bung, etc. And after the 3rd install, replacing both the totally saturated OEM charcoal canister and OEM fill line assembly ($$$) the issues developed even with only city driving, again after running through about a tank of fuel as in the first two installs. When I went to fill my OEM tank a second time, these re-occurring issues cause almost immediate OEM-side fuel neck backup, and station fuel pump 'click off', with even the lightest possible flow rate of the station pump. I about cried that day, realizing a 3rd install didn't resolve it. As usual, it took about 20 minutes to fill the OEM tank, and any 'click off' events (often unavoidable) seem to lead to drips above the LRA tank somewhere, and increased gas smells.

Long horror story short, the best assessment of what is going on is that doubling the fuel capacity of the vehicle is overwhelming the main charcoal canister, which actually takes running through about a tank or two of fuel to 'foul', and realize things are amiss. I've become an expert in this terrible scenario, but I'm not a mechanic or automotive engineer. Apparently, this is specifically problematic in 2006/2007 LCs after the evap system re-design, assuming that information is correct...???

I've heard in the wind that this primary 'fouled canister' causing the venting, filling or overflow issues has been resolved by adding a 2nd OEM charcoal canister, specifically in series, to process the additional vapor and limit venting issues and backups. Regarding fuel boiling, I hear from the 200 forum that you can place fuel line coolers to help with that issue - which I suspect is aggravated by the primary venting issues.

My questions to you all are:

1. Does anyone else have an 06 or 07 LC, with an Aux 24 install, where you are NOT having issues? If so, I'd like to compare notes and tell you how lukcy you are.
2. Can any 100 series fuel system gurus confirm if there truly was an evap system re-design in late-years 100 series, and when specifically did that happen and what was changed?
3. Has anyone heard of, or themselves have, an 06-07 LC where there are TWO charcoal canisters installed to handle this additional vapor load? Is this a good/bad/OK idea to test and why?
4. Are there any other ideas of what I can try?
5. Where would liquid fuel be exiting the system - possibly at the saturated charcoal canister? (UPDATE 04/20/22 - FOUND A CRACK IN A FACTORY CORNER WELD ON THE LRA TANK, THAT'S BEEN THERE FROM THE VERY BEGINNING. RE-WELDED, LINED, AND PUTTING BACK INTO SERVICE)
6. Does anyone know a therapist specializing in Land Cruiser fuel system PTSD?

Thanks, please help end my suffering. I need this system to work for a series of South America trips where Jerry cans are not a viable solution. When it's working properly, the LRA system is a game changer for range, as many of you know. It just seems it was not fully developed/tested for all US-version 100 series vehicles by the Aussie's.

Fritz

 

[OEMGUY0720]

Hey Fritz, sorry to hear about your dilemma. I have an 06 too, the LRA is a good solution for me but that’s on the latter part of my list. From experience I had venting issues too in the past on this specific vehicle model. My first question is, have you by chance replaced your oem fuel pump already? If yes, what part number did you use?

Reason for me asking is that the 06 and the 07 models uses a unique fuel pump (2-speed) and can be related to under (stalling) / over (venting) fuel pressurization. For most of what the 06 and 07 owners including me have experienced aside from stalling at high elevations or with high ambient outside temperatures is the excessive venting on the gas gap and that concerning fuel smell.

Replacing the fuel pump fixed my stalling issues during the hot dry summer season here in Las Vegas as well as the venting issues experienced when we went up to 10k elevation at Kanab UT.

 

[suprarx7nut]

I think the evap system is inadequate in the 100 series - perhaps worse in the 06/07 or whatever years saw the redesign. Multiple CC canisters might help (I would run in parallel), but if you're not identifying the flow restriction, that extra CC canister might not really help. You need to ensure the system is purging the tank properly and ten CC won't do that much better than 1 if the outlet from the tank and inlet to the engine are only sized big enough for 1 canister. Eventually the CCs will saturate unless they are effectively vented into the engine.

There's also a temperature problem where the returning fuel can be warmed too much and cause excessive evaporation. You can improve fuel cooling with strategically placed and/or relocated fuel lines.

 

[GTV]

@LastTry
1) I have an '07 and don't have an auxiliary tank because of all the issues I've seen on this and the 200 series forum.
2) According to LRA the change occurred in May of 2004, you must provide your VIN when purchasing a larger main tank to confirm it doesn't have the updated evap system.

Sorry I can't be of much more help than that. LRA is not interested in making (modifying, really) a larger main tank for the U.S. spec late 100's, I asked and was basically blown off by the American and Australian contacts. It's too small of a market for them to bother with, apparently. They wouldn't even share with me what made the late tanks different so I could make my own modifications.

My plan is to get a complete OEM late model tank, filler, etc. and a 40 gallon early 100 LRA main tank and figure out what needs to happen to make it work. It absolutely has to be possible. I kinda hate the idea of giving them any of my money considering I was blown off and not taken seriously but it's either that or unload my '07 for an earlier model.

 

[porkandcorn]

Hey Fritz, sorry to hear about your dilemma. I have an 06 too, the LRA is a good solution for me but that’s on the latter part of my list. From experience I had venting issues too in the past on this specific vehicle model. My first question is, have you by chance replaced your oem fuel pump already? If yes, what part number did you use?

Reason for me asking is that the 06 and the 07 models uses a unique fuel pump (2-speed) and can be related to under (stalling) / over (venting) fuel pressurization. For most of what the 06 and 07 owners including me have experienced aside from stalling at high elevations or with high ambient outside temperatures is the excessive venting on the gas gap and that concerning fuel smell.

Replacing the fuel pump fixed my stalling issues during the hot dry summer season here in Las Vegas as well as the venting issues experienced when we went up to 10k elevation at Kanab UT.

New 2-speed fuel pump. This is great. I'll put that on my solutions list for my 4th install.... I'm willing to try anything at this point.

 

[porkandcorn]

I think the evap system is inadequate in the 100 series - perhaps worse in the 06/07 or whatever years saw the redesign. Multiple CC canisters might help (I would run in parallel), but if you're not identifying the flow restriction, that extra CC canister might not really help. You need to ensure the system is purging the tank properly and ten CC won't do that much better than 1 if the outlet from the tank and inlet to the engine are only sized big enough for 1 canister. Eventually the CCs will saturate unless they are effectively vented into the engine.

There's also a temperature problem where the returning fuel can be warmed too much and cause excessive evaporation. You can improve fuel cooling with strategically placed and/or relocated fuel lines.

Oh s***. If Yota's on the case, my problems are as good as solved! Good to hear from you again and I still owe you a beer for all your help with my AHC tuning. Regarding a 2nd canister, why do you say run in parrallel and not in series? I've actually heard it suggested that in series was the way to go?

 

[OEMGUY0720]

This is the part number, and try not to forget to transfer that critical rubber o-ring (red arrow) from the old to new, otherwise your engine won’t start.

 

[LastTry]

Hello Fellow Late 100 Series in counseling re our beloved LRA aux tank. I am guessing its been a year of some same issues. I too am no trained mechanic, cut my teeth on a '66 VWSquareback rebuilds (blew the first time) hard school of fix it, tore it apart a d redo. Sadly my So American dream excursion is not happening. I pushed the envelope to add convenience with an aux tank. It worked a few times but flooded my 07 evap and choked the engine. So out it comes and canister backup is my new life.

 

[porkandcorn]

This is the part number, and try not to forget to transfer that critical rubber o-ring (red arrow) from the old to new, otherwise your engine won’t start.View attachment 2924114

To clarify: is the Denso 950-0210 and aftermarket part that you recommend using to replace the OEM Toyota part (which is usually a 5digit-5digit part number? aka, what is the difference between these two parts in the image?

 

[OEMGUY0720]

To clarify: is the Denso 950-0210 and aftermarket part that you recommend using to replace the OEM Toyota part (which is usually a 5digit-5digit part number? aka, what is the difference between these two parts in the image?

The difference is just the part number (sorry I would have to look up the original part number and get back with you). Both are made by Denso which is the component provider of Toyota/Lexus. But if my memory serves me right, the old part number is no longer in production and has been replaced with part number 950-0210. Which is also used by the Tundra Platform which share the same motor with the VVTi (that experienced the same symptoms of stalling under high temps/high altitudes).

 

[suprarx7nut]

Oh s***. If Yota's on the case, my problems are as good as solved! Good to hear from you again and I still owe you a beer for all your help with my AHC tuning. Regarding a 2nd canister, why do you say run in parrallel and not in series? I've actually heard it suggested that in series was the way to go?

Ha! I wish. I haven't been able to test much on the evap system. Got a data logger, fuel temp, pressure gauges, etc... aaaaaand it's all been sitting in my garage for 9 months.

I say in parallel because if you run in series it only takes one canister to become clogged or restrictive and you're toast. I believe (I say believe because I do not have observed measurements beyond basic ODB data yet) that the core problem is insufficient vapor flow. The evap valve flat out turns off during lots of slow paced driving/idling, coasting (easy to verify with Torque or similar app via OBD port). I think the system is barely good enough under ideal circumstances and if you combine some combo of heat/ethanol/sloshing you just overwhelm it and the inevitable result is fuel spewing out the last ditch safety relief in the neck/cap. If you run another CC in series, that adds some absorbing capacity, but it does nothing to help flow. If anything, it further restricts it. Running in parallel would potentially increase it, but again, you'd have to ensure it can flow plenty via the tank outlet and engine inlet.

Hello Fellow Late 100 Series in counseling re our beloved LRA aux tank. I am guessing its been a year of some same issues. I too am no trained mechanic, cut my teeth on a '66 VWSquareback rebuilds (blew the first time) hard school of fix it, tore it apart a d redo. Sadly my So American dream excursion is not happening. I pushed the envelope to add convenience with an aux tank. It worked a few times but flooded my 07 evap and choked the engine. So out it comes and canister backup is my new life.

Just another anecdotal piece of evidence for me that the problem is with the factory evap system. Larger tank has more surface area and we can assume a higher rate of evap which requires an even more capable evap system than the apathetic one on the 100.


I think the quick and easy approach is to try to limit heat going into the fuel line. You can re-route lines and add some heat shielding to the lines/tank. I don't think that's the complete solution, but it's a quick and simple way to improve things.

 

[Toyoland66]

Adding a 2nd charcoal canister is not a viable solution. This gen Toyota uses a leak detection evap system that has a valve that closes off the systems vent, and a vacuum pump that draws down the system once the valve is closed to check for leaks. The vent to atmosphere has to be controlled by this valve or the system will throw codes.

The US evap system is unique compared to other markets. Most markets have the charcoal canister mounted in the engine compartment and no leak detection. The US system has a small diameter filler vent and a large diameter vent to the charcoal canister. The charcoal canister is intended to filter fumes upon filling, whereas the non US systems have a large diameter filler vent to the filler neck that allows the tank to vent straight to atmosphere while filling. The US spec charcoal canister vent to atmosphere is to a sleeve that surrounds the filler neck but is outside of the sealed system. I think a lot of people who have reported fuel burping out of their filler neck are mistaking this sleeve for the actual filler. If fuel is burping out of this vent it will come out of the filler door.

My experience is based on adding the OEM subtank to my 120, so may not apply, take it with a grain of salt or whatever saying you want to apply. I think that the LRA system, in order to comply with US emission regs is trying to force filler venting for both tanks through the charcoal canister during filling, which overwhelms the system and results in fuel going into the charcoal canister during filling, which reduces the life of the canister, and will result in liquid fuel burping out of the filler door.

In contrast the Gulf or Aussi spec OEM subtank vent straight to the filler neck when filling, which is open to atmosphere during filling but sealed when the gas cap is installed. This system bypasses the evap system completely when filling. I think the solution is to run a larger vent to the filler neck inside of the sealed system i.e. inside of the gas cap which requires installing a non us spec filler neck and a separate vent to atmosphere for the evap system. This assumes the LRA tank has a separate vent to filler and a seperate vent to evap which it may not.

 

[porkandcorn]

Adding a 2nd charcoal canister is not a viable solution. This gen Toyota uses a leak detection evap system that has a valve that closes off the systems vent, and a vacuum pump that draws down the system once the valve is closed to check for leaks. The vent to atmosphere has to be controlled by this valve or the system will throw codes.

The US evap system is unique compared to other markets. Most markets have the charcoal canister mounted in the engine compartment and no leak detection. The US system has a small diameter filler vent and a large diameter vent to the charcoal canister. The charcoal canister is intended to filter fumes upon filling, whereas the non US systems have a large diameter filler vent to the filler neck that allows the tank to vent straight to atmosphere while filling. The US spec charcoal canister vent to atmosphere is to a sleeve that surrounds the filler neck but is outside of the sealed system. I think a lot of people who have reported fuel burping out of their filler neck are mistaking this sleeve for the actual filler. If fuel is burping out of this vent it will come out of the filler door.

My experience is based on adding the OEM subtank to my 120, so may not apply, take it with a grain of salt or whatever saying you want to apply. I think that the LRA system, in order to comply with US emission regs is trying to force filler venting for both tanks through the charcoal canister during filling, which overwhelms the system and results in fuel going into the charcoal canister during filling, which reduces the life of the canister, and will result in liquid fuel burping out of the filler door.

In contrast the Gulf or Aussi spec OEM subtank vent straight to the filler neck when filling, which is open to atmosphere during filling but sealed when the gas cap is installed. This system bypasses the evap system completely when filling. I think the solution is to run a larger vent to the filler neck inside of the sealed system i.e. inside of the gas cap which requires installing a non us spec filler neck and a separate vent to atmosphere for the evap system. This assumes the LRA tank has a separate vent to filler and a seperate vent to evap which it may not.

Thanks Toyoland66 for the obviously informed analysis.

Now that you mention this valve that closes off the vent, I now recall that my Toyota mechanic mentiioned this valve as well. I *believe* he indicated that the valve could be getting stuck in that closed position, though I don't recall his thoughts about why that could happen.

Is the solution you propose something that you could represent in a sketch? That would help me better understand precisely what you are describing.

 

[LastTry]

I'm getting a headache.

 

[suprarx7nut]

Thanks Toyoland66 for the obviously informed analysis.

Now that you mention this valve that closes off the vent, I now recall that my Toyota mechanic mentiioned this valve as well. I *believe* he indicated that the valve could be getting stuck in that closed position, though I don't recall his thoughts about why that could happen.

Is the solution you propose something that you could represent in a sketch? That would help me better understand precisely what you are describing.

This diagram is from the Lexus manual for an 06.

 

[GTV]

This diagram is from the Lexus manual for an 06.

View attachment 2924720

I'd be curious to know how this schematic compares to that of a pre May 2004 built vehicle.

I'd also like to know how the evap system on a 100 with a factory sub tank differs from that which LRA offers.

 

[J1000]

The EVAP/charcoal canister is the same on the late 100s as what comes on Prius, Scions, and Camrys of the same era. They are definitely undersized and cause problems on stock 100s. But there is also a second problem of excessive heating of the fuel by the engine and exhaust on the 100. I documented the 4 best things I did in this post: Gas tank building excessive pressure & fuel smell. Dangerous for sure! Why does this happen? - https://forum.ih8mud.com/threads/gas-tank-building-excessive-pressure-fuel-smell-dangerous-for-sure-why-does-this-happen.1214321/page-11#post-13251496

Like I said spewing fuel out of the filler cap after climbing a mountain on a hot day is something just about every 100 owner can attest to. That's probably not being caused by the LRA tank, but maybe exacerbated by it.

 

[suprarx7nut]

I'd be curious to know how this schematic compares to that of a pre May 2004 built vehicle.

I'd also like to know how the evap system on a 100 with a factory sub tank differs from that which LRA offers.

At your service. Here's the 99LC system.

 

[porkandcorn]

Here's from "grinchy" on the 200 forum that I hijacked on this topic.

 

[porkandcorn]

Also, I've been collecting, and will continue to collect and condense a comprehensive list of possible solutions for those having these issues. These are from mudders on both the 200 and 100 forums. I don't entire understand all these solutions, but I will continue to learn, and place the ideas in the hands of people more versed in this stuff who can help me. I'm particularly interested in items #9 and #10 at the end of the list, based on my experience with this:

(Edited March 5, 2022)

1. Install new dual-speed fuel pump, fixed fill issues for some people.
2. Place inexpensive fuel cooler on fuel return line (for fuel boiling)
3. There's a heat barrier product that I've used around my LRA tank near the muffler.
4. There's a couple other things to check. Purge VSV is not leaking and causing the fuel system to be under vacuum. Or charcoal canister vent filter/VSV, and making sure these aren't plugged. Both can cause slight vacuum in the fuel system which can cause fuel to boil more easily leading to your symptoms.
5. Fuel sold at higher elevations may have slightly different formulations to reduce vapor pressure, so if you often fill up at low altitudes and go to high altitudes...maybe something to consider. Utah fuel can be suspect, especially in a hot state with altitude to climb.
6. BUT I suspect you have a problem with the evap. box and not the aux LRA Tank. You could put a water pressure gauged t-taped into the main tank vent to gauged what pressure amount is building up and see how high it is. I think it is your evap. release value causing the issue, and you can test this easy. When you turn off the vehicle the pressure should drop to zero. Then when you remove the fuel cap there should be no pressure at all. If you have pressure the evap. valve is not working correctly.
7. If you turn off the engine and the tank or gas cap is under pressure then this evap. valve is not working or the evap lines are hooked up wrong. Now it is important that when you installed the tank you maintained the "green" lines which vent to the atmosphere. If you attached the green line to the fuel filler you will have an issue that could cause that problem of over pressure and not releasing the pressure as there is no escape for the pressure then. This will also cause filling issues. So I would take a good look at how it is hooked up first. Make sure that line from the canister vents to the atmosphere for pressure relief. Then if it is hooked up "for sure" correctly then it's likely the valve. Did the issue start immediately after install? Then I would check that line in green on the diagram carefully. Diagram by grinchy (back a few pages)
8. Well I was thinking if that evap hose it not routed correctly and has been routed to the filler instead of the atmosphere, then there is no escape for the pressure. So I was thinking 1 of 2 things is going on. 1. If the Evap line is routed wrong Even if the valve is working and opens it is going to open the evap line to the enclosed filler area. Then no escape for the pressure. Or 2. The Evap line is routed correctly but the valve is not working. Since you installed a new evap box, likely #1. Evap line routed incorrectly. Even if the fuel was "hot" I would look at that as a 2nd issue .. and the pressure should still escape if the evap line is routed correctly and the valve is working correctly.
9. Adding a 2nd charcoal canister is not a viable solution. This gen Toyota uses a leak detection evap system that has a valve that closes off the systems vent, and a vacuum pump that draws down the system once the valve is closed to check for leaks. The vent to atmosphere has to be controlled by this valve or the system will throw codes. The US evap system is unique compared to other markets. Most markets have the charcoal canister mounted in the engine compartment and no leak detection. The US system has a small diameter filler vent and a large diameter vent to the charcoal canister. The charcoal canister is intended to filter fumes upon filling, whereas the non US systems have a large diameter filler vent to the filler neck that allows the tank to vent straight to atmosphere while filling. The US spec charcoal canister vent to atmosphere is to a sleeve that surrounds the filler neck but is outside of the sealed system. I think a lot of people who have reported fuel burping out of their filler neck are mistaking this sleeve for the actual filler. If fuel is burping out of this vent it will come out of the filler door. My experience is based on adding the OEM subtank to my 120, so may not apply, take it with a grain of salt or whatever saying you want to apply. I think that the LRA system, in order to comply with US emission regs is trying to force filler venting for both tanks through the charcoal canister during filling, which overwhelms the system and results in fuel going into the charcoal canister during filling, which reduces the life of the canister, and will result in liquid fuel burping out of the filler door. In contrast the Gulf or Aussi spec OEM subtank vent straight to the filler neck when filling, which is open to atmosphere during filling but sealed when the gas cap is installed. This system bypasses the evap system completely when filling. I think the solution is to run a larger vent to the filler neck inside of the sealed system i.e. inside of the gas cap which requires installing a non us spec filler neck and a separate vent to atmosphere for the evap system. This assumes the LRA tank has a separate vent to filler and a seperate vent to evap which it may not.
10. (From Ward Harris - Long Range America (distributor): Given common features of the late 100 and 200 Series emission systems, it seems likely that at least part of the problem (along with canister capacity) is related to replacement of the stock canister vent connection to the OE filler neck, replaced with a mushroom filter and extension line. One might consider a stock filler neck that will continue the “collar” vent connection, but modified to allow for a second tank fill line.
11. 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.