LRA aux tank and slight gas smell
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CharlieS
GOLD Star
I might not be sensitive enough, but I don't notice fuel smells and don't throw any codes with my LRA.
Note: I do have the k&n filter and larger vent hose as recommended by @TeCKis300.
Note: I do have the k&n filter and larger vent hose as recommended by @TeCKis300.
Julian73
SILVER Star
Thanks greatly. I suppose the expediant way to replicate the OEM Sub tank style would be to retain Stock (USA) routing but add Evaporative venting line from Sub to Main. Now whether the lines are large enough and whether two new issues are created for one potential issue who knows. I haven't even ordered any parts for the system yet, but maybe if I get the LRA 12.5 gal, i'll preconfigure it with and extra vent tape off prior to installation.
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Julian73
SILVER Star
Nor any hydrolocks where a line dips below the fill level of either tank.
Thanks for all the comments in here. Here's my story/nightmare with my 2006 LC and an LRA 24Aux:
My LRA Aux 24, installed in July of last year, has been plagued with issues, including - fill 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 (distributor) most highly recommended shop. After issues developed, it was pulled and re-installed by that same shop. The next week, when climbing a rough pass in Utah's Henry Mountains, we pulled over at the summit to realize that hot vapor was blasting out of the gas door. It took 30 minutes to carefully depressurize the system. 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 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 year 100 series cruisers.
The distributor, Long Range America, 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. 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" bungs on the fill neck to limit fouling, 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 about a tank of fuel as in the first two installs. When I went to fill my OEM tank a second time, venting issues cause almost immediate backup, and station fuel pump 'click off', with even the lightest possible flow rate of the station pump. Takes about 20 minutes to fill the OEM tank, and any 'click off' events seem to lead to drips above the LRA tanks, and major 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. 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' cause has been resolved by adding a 2nd OEM charcoal canister, specifically in series, to process the additional vapor.
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. Was there truly 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?
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.
Fritz
My LRA Aux 24, installed in July of last year, has been plagued with issues, including - fill 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 (distributor) most highly recommended shop. After issues developed, it was pulled and re-installed by that same shop. The next week, when climbing a rough pass in Utah's Henry Mountains, we pulled over at the summit to realize that hot vapor was blasting out of the gas door. It took 30 minutes to carefully depressurize the system. 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 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 year 100 series cruisers.
The distributor, Long Range America, 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. 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" bungs on the fill neck to limit fouling, 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 about a tank of fuel as in the first two installs. When I went to fill my OEM tank a second time, venting issues cause almost immediate backup, and station fuel pump 'click off', with even the lightest possible flow rate of the station pump. Takes about 20 minutes to fill the OEM tank, and any 'click off' events seem to lead to drips above the LRA tanks, and major 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. 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' cause has been resolved by adding a 2nd OEM charcoal canister, specifically in series, to process the additional vapor.
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. Was there truly 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?
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.
Fritz
CharlieS
GOLD Star
That's a bummer. Hope you get it sorted. Are you aware that this is the 200 series forum? I don't think we've been seeing the same issues with the 200. I know I am one of the lucky ones that hasn't had any issues on my 200.
I didn't notice it was a 200 forum... thanks for that. I'll find a thread in hundo-land.
@porkandcorn the altitude fuel boiling does happen on 200. Speculation is that it is because the fuel is used for engine cooling and then sent back to the tank. Not sure if the 100 engine also has this feature. If so, maybe you could consider mounting a fuel cooler on the fuel return line? They are relatively inexpensive, finding a place for it is likely the challenge.
Sorry to hear of your challenges.
Even though this is the 200-series forum, the aux tank and emissions architecture still have a lot in common.
May I ask what other mods you have on you hundy? Specifically, do you have underarmor and skids?
US fuel in the last decade has had reformulations with more ethanol/corn oil. This leads to higher evaporation and vapor pressure. There's no single factor but it's a delicate balance of vapor pressure, heat, and barometric pressure. 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.
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.
I don't know what the 100-series setup looks like, but maybe even muffler can being too near the aux tank combined with lots of slow driving or off-roading, can add heat and vapor pressure in the fuel tank system. Same with the under-armor I mentioned earlier.
Thanks for the thoughts, TeCKis300. Fueling boiling has only been an issue that one time, but good to think about these things holistically. My primary issue is trouble filling up, leaking gas, and smell. I do have Dissent's 3-piece aluminum skid plate set, and perhaps I need to look into having that CNC'd to allow the OEM tank to better breath during those climbing events.
Here's my 100 Series forum post on this topic in case anyone finds this and wants to switch over, and give me insight over there where it belongs:
2006 LC w/ LRA Aux 24 - Fill, Venting, Fumes, Dripping & Over-Pressurization Issues
No problemo. The 200-series is not immune and has had similar challenges. Boiling happens with stock rigs too, notably in Moab.
If you're having trouble filling up, you might look at the vent/breather for the charcoal canister. I've had this issue with too much silt (from off-roading) caking the vent filter. Once I resolved that, I've not had fill issues since, and will stay on top of cleaning the breather. Keep that breather high up to keep fumes from venting out when parked.
Charcoal Canister / LRA Breather Fix
TL;DR 1) LRA charcoal breather plumbing and adapters are too small in diameter, limiting venting when filling the main tank tripping the gas pump. Needs 5/8" ID plumbing though to breather. 2) Breather filter is a maintenance item. Too much dust and dirt will plug the external breather filter...
forum.ih8mud.com
Definitely look at the skids. There's at least one company here that was prototyping skids. Immediately had fuel boiling issues on their rig testing. Took off skids and problem solved.
Thanks, I was having the fueling/venting issues before the skids, but had boiling issue after. Good to think about. 5/8" vent filter is high, tight and clean as a whistle after my 3rd install (city driving only) and same issued developed. It seems to take time for the canister to foul, which makes it really hard to troubleshoot.No problemo. The 200-series is not immune and has had similar challenges. Boiling happens with stock rigs too, notably in Moab.
If you're having trouble filling up, you might look at the vent/breather for the charcoal canister. I've had this issue with too much silt (from off-roading) caking the vent filter. Once I resolved that, I've not had fill issues since, and will stay on top of cleaning the breather. Keep that breather high up to keep fumes from venting out when parked.
Charcoal Canister / LRA Breather Fix
TL;DR 1) LRA charcoal breather plumbing and adapters are too small in diameter, limiting venting when filling the main tank tripping the gas pump. Needs 5/8" ID plumbing though to breather. 2) Breather filter is a maintenance item. Too much dust and dirt will plug the external breather filter...
Definitely look at the skids. There's at least one company here that was prototyping skids. Immediately had fuel boiling issues on their rig testing. Took off skids and problem solved.
Re the boiling .. I saw back on post #54 on this thread the picture of the "return tube" is at about the 2/3 level of the 200 tank, and this return tube wrap around to cool the return fuel.
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.
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.
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Another good idea. I'll put it on the list.
I think he's replaced his evap box before. That in my mind would eliminate it as the culprit. There is some other system factor that's causing his issues. Namely I believe there's some fuel heating issue due to peripheral mods, hence my question about skids.
In regards to the tank, it's generally open to atmosphere by way of the charcoal canister breather. This should have the tank nominally at neutral pressure. There are occasions that we know the breather VSV does close and it's likely in cases where there's excess vapor pressure (see point above), and the emissions requirement is to suppress that. So the tank will pressurize, which should increase the boiling point to minimize vapor - to a degree. Once the vapor pressure becomes excessive to the design pressure point of the fuel tank system, it's the responsibility of the gas cap as a safety valve to vent. For others, don't open the gas lid in this situation, as it'll boil even more.
The evap canister's job is to capture fuel vapors. It itself cannot manage excessive fuel vapor/liquid from a situation where the fuel is boiling. It's the responsibility of the overall system design is to manage vapor pressure and avoid boiling.
What we see in @grinchy OE aux tank is the evap line cooling circuit to cool fuel vapor so that it condenses back into the tank. So excess fuel vapor doesn't get to the evap. The LRA setup doesn't work like that as it maintains the breather via the factory tank. LRA aux tank vents to the gas fill neck (that likely also serves as a cooler), then back to the factory tank. Nothing wrong with this setup. Neither can likely manage the situation where fuel is overheated and producing excessive vapors.
The more I think about @porkandcorn problem, the more convinced I am that his fuel system is fine. There's a modification upstream that's causing thermal issues. It would also speak to his inability to fill gas, as the gas tank seems to be always under pressure - again the thermal issue. Rather than what I was thinking with clogged breather.
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bloc
SILVER Star
Toyota having issues with fuel boiling in the tank at altitude in totally stock 200s suggests their evap system isn't up to the job.. and adding another tank that drastically increases surface area will not help the situation. Adding another charcoal canister to increase capacity seems logical but I don't know that they work effectively in series. My understanding is it is possible to "poison" them with too much fuel vapor (or maybe it needs liquid fuel) and ruin them completely. As long as the flow pressures remained even I don't see why we couldn't run two CCs in parallel though.. unless they have electrically controlled valves that can't run from a solitary control signal. If the electronics are merely sensors then having a dummy CC may still work.
I might need to do some digging to see what electronics are in our charcoal canisters.
@porkandcorn I had a look at the parts diagrams and there are substantial differences between the pre 2006 and 06/07 100-series evap systems.
Toyota has used fuel pressure regulators that return hot fuel from the rails to the tanks for.. a very long time. Including the 100, definitely.
I think the idea that it is to cool the engine is incorrect. It will keep cooler fuel in the rails than would be there if the system is returnless.. sending warm fuel back to the tank where it can cool via convection and conduction through the tank wall in a cooler environment than the engine bay.
I might need to do some digging to see what electronics are in our charcoal canisters.
@porkandcorn I had a look at the parts diagrams and there are substantial differences between the pre 2006 and 06/07 100-series evap systems.
Toyota has used fuel pressure regulators that return hot fuel from the rails to the tanks for.. a very long time. Including the 100, definitely.
I think the idea that it is to cool the engine is incorrect. It will keep cooler fuel in the rails than would be there if the system is returnless.. sending warm fuel back to the tank where it can cool via convection and conduction through the tank wall in a cooler environment than the engine bay.
This isn't a Toyota issue necessarily. The EPA and federal agencies have been playing games, allowing for increased Reid vapor pressure on account of Ethanol. Some states get additional wavers, increasing pressure. This is also why we have summer and winter blends.
Any stock system has design balances with margin. The return system is a Red Herring and has always been factored into the stock system. Add skids, and to your point add aux tank, and whatever other variables, and we may be on the wrong side of design parameters.
bloc
SILVER Star
I vaguely remember reading 4Runners and maybe Tacomas on the same trails as us don’t deal with the same issues though. Could be wrong. But even those are toyota designed systems.. maybe better tweaked for the US market and our fuel standards..
Regarding fuel boiling, other than ensuring there are not heat sources near fuel tanks/line, not skid plates/etc covering tanks, and potentially placing a fuel cooler on the fuel return line, what can the stock or modified LC owner do at elevation, on really hot days, or hot days + elevation to control system pressure for safety?
My assumption is that one would stop, the vehicle at elevation intervals, turn off the vehicle, carefully bleed pressure from the gas cap, restart, and carry on your merry way. Is this correct and wise?
My assumption is that one would stop, the vehicle at elevation intervals, turn off the vehicle, carefully bleed pressure from the gas cap, restart, and carry on your merry way. Is this correct and wise?
