Dave From Toyota - What We Learned In Breck About The 200...

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My guess would be the altitude and bouncing combined with long term going up hill. :cool:
 
@kreiten and someone else's did that last year on hells revenge. I remember we heard what sounded like a boiling sound coming from the Bowles of the fuel tank. Not cool. And to @Canyonero 's point I don't recall anyone with the upset fuel tank syndrome mentioning a dash light or anything like that going off. Must be one of those weird unexplained Moab phenomenon deals. Special at best.
 
I do think it's probably Moab, maybe someone with a meteorological background can explain why. Higher air density?

I wheel at much higher altitude than Moab - often over 11,000 feet. Steep, rocky and also often in high heat out here in Colorado - I've never had the gas issue in Colorado, only in Moab (personally as of this last trip) and I've witnessed other trucks do it from build years 2008-2015.

Found this - "Furthermore, the small change in air density caused by a small difference between actual air temperature and standard air temperature at any altitude point tends to be offset by the change in air density caused by a small difference between actual barometric pressure and standard barometric pressure at that altitude point. This is because a higher-than-normal temperature (a warm, balmy day) tends to be accompanied by a higher-than-normal barometric pressure of the atmosphere. That is, high temperature tends to decrease air density, while high pressure tends to increase air density."
 
It's a thunder storm
 
more like a sh!t storm :flipoff2:

It was a long week....
 
I do think it's probably Moab, maybe someone with a meteorological background can explain why. Higher air density?

I wheel at much higher altitude than Moab - often over 11,000 feet. Steep, rocky and also often in high heat out here in Colorado - I've never had the gas issue in Colorado, only in Moab (personally as of this last trip) and I've witnessed other trucks do it from build years 2008-2015.

Found this - "Furthermore, the small change in air density caused by a small difference between actual air temperature and standard air temperature at any altitude point tends to be offset by the change in air density caused by a small difference between actual barometric pressure and standard barometric pressure at that altitude point. This is because a higher-than-normal temperature (a warm, balmy day) tends to be accompanied by a higher-than-normal barometric pressure of the atmosphere. That is, high temperature tends to decrease air density, while high pressure tends to increase air density."

I'll do my best Cliff Clavin here :) The air would be less dense, as air is heated it expands, so for a given volume hot air is less dense. In aviation for calculating performance, we must take into account density altitude at all times. At sea level standard atmosphere is 15 degrees C and 29.92"/hg., Denver (not at sea level) has it's own "standard atmosphere", and any deviation from that must be taken into account. Runway length and takeoff run, max takeoff weight, climb performance etc.

I personally don't think any of that has to do with the vapor/fluid escaping from the fuel system/tanks. I'm no engineer but a sealed fuel system, slow speeds, slick rock radiating heat.

Maybe MOAB needs to be added to Mr. T's test bed?
 
We were having fun in St Anthony ID sand dunes this past spring at 5000 ft and about 70 deg f. Many steep climbs up the sand dune face with nothing but blue sky in the wind shield and the same very steep drops off the edge of a dune. After one of those steeper than the last and a bit uncomfortable steep slides down the face we smelled fuel. Inspecting all fuel related points we could not find any leaks. I did not remove the gas cap. The fuel smell was coming from the back of the vehicle. When the group of trucks stopped, I would park down wind of the rest of them. This went on for about another 30 min of driving then stopped smelling like fuel. I decided it must have been from such a steep nose down angle of the vehicle with at least 3/4 of a tank of fuel but no visible fuel loss.
There were no strange weather systems in the area just lots of sand.:steer:
 
I won't get too nerdy but if you look up the Clausius-Clapeyron equation, it describes the variables that model when a fluid boils. Obviously heat and pressure. I believe Moab is a combination of multiple factors that affect heat and pressure. It's likely the elevation gain (loss of barometric pressure), combined with hours of low speed crawling that heats up the underbody/fuel significantly.

Gasoline readily vaporizes at temps as low as 100 degrees. Components of it can begin boiling at something like 105 degrees F. Certain additives, especially ethanol, will make it boil at even lower pressures. Combine all that with significant elevation gain, and I can certainly see it happening.

Old school cars used to have vapor lock issues sputtering at low speed around town. Or crawling along with parades. At least the LC keeps trucking.
 
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My biggest issue with the fuel smells and issues is that I've been driving the same routes and trails in Colorado and Utah for about 16 years, and I've never had any fuel smell issues with any vehicle other than the 200. I've driven all kinds of Toyotas and Jeeps in the same elevation and weather and trails without the issues, so I don't think it has as much to do with the environmental issues as much as it has to do with the 200 itself and its fuel or emissions setup.

FWIW I decided to try a new gas cap on mine, and the part number has changed recently for the 200 and appears a bit different than the old one. No issues yet with the new cap with 3 days in the mountains, so perhaps that was the culprit.
 
admittedly, i don't have a real answer to this, but since seeing this issue, i've researched it... i've seen the same 'fuel smell/fuel-boiling-out-of-filler' issue on sites related to motorcycles, mazda miatas, ferraris, etc... it seems to present itself under the same circumstances. i think it's the same, based on what i've read. the issue sounds the exactly the same and it presents itself in VERY similar ways. none of the sites have offered a scientific explanation that satisfies me (i come from a math/science background), but they have all described very, very similar circumstances - strong smell of gas coming from near the charcoal canister - wherever that happens to be; "boiling" of gas from the filler; massive pressure at the gas cap... the consensus has been that the combination of altitude change and under-car heat near the fuel tank result in an expansion within a sealed fuel system. this overwhelms the underpowered relief valve on the gas cap and the lower pressure over a very short period of time, given the elevation change, results in the gas "boiling" (or percolating, if you read what's happened to people with carburated engines that deal with vapor lock).

again, i'm no expert...
 
Toyota engineers planned the fuel consumption in front to exceed fuel leakage in the rear.....

engineering principle:

engine fuel suckage > mass of fuel in tank= no leakage

*sounds like people with leaks need gears and larger tires to solve this problem*

- again- " im no doctor , i just play with myself on tv."
 
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My biggest issue with the fuel smells and issues is that I've been driving the same routes and trails in Colorado and Utah for about 16 years, and I've never had any fuel smell issues with any vehicle other than the 200. I've driven all kinds of Toyotas and Jeeps in the same elevation and weather and trails without the issues, so I don't think it has as much to do with the environmental issues as much as it has to do with the 200 itself and its fuel or emissions setup.

FWIW I decided to try a new gas cap on mine, and the part number has changed recently for the 200 and appears a bit different than the old one. No issues yet with the new cap with 3 days in the mountains, so perhaps that was the culprit.

Worth a try. New part #? Thanks.

edit: Looks like this is the part number, 77300-53020,
listed for the 2017 Land Cruiser.
Filler Cap - Toyota (77300-53020)

And here's the old part, 77300-06040.
Toyota Land Cruiser (2006-2014) OEM Genuine GAS CAP 77300-06040 | eBay
 
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This is my 2013 rig at about 9,000 feet. Maybe around 85F+ degrees. Off road and a lot of sloshing around.

Also had the same issue in my 1999 100 Series.
 
I was driving right behind TonyP all the way up Top of the World in Moab this year...and his fuel wasn't just boiling with vapor....it was literally RUNNING OUT in TWO STREAMS out of his truck... -As much volume as when someone fails to completely turn off a bathroom faucet. I mean a LOT of fuel literally pouring in two thin streams.

Last year, my own truck fuel did the "boiling" routine on Top of the World, and nowhere else. This year? Didn't really have the issue.

Sooooo strange.
 
I agree that it's likely not anything design specific aspect of the 200-series. It's basically what happens when the fuel gets hot enough, and atmospheric pressure low enough, ALONG WITH the formulation of the specific fuel that may lower its boiling point. Ethanol has been known to significantly decrease (10 degress +) the boiling point of fuels. I suspect it's the advent of more ethanol content fuels.

In regards to weak caps and relief valves... I'm not so sure it's something to be resolved. These relief valves are for safety. Too much pressure in a closed vessel starts to begin sounding like a bomb. The more pressure, the more boom, if there were to be ignition. I'm not so comfortable with vapors pouring out either as that brings the fuel closer to more potential ignition sources.

Then again, not sure I've ever read about any specific scenario of gas vapors off road resulting in a conflagration?
 
wonder if a diesel would have had the same issue as the gas if placed in the same scenario
 
I agree that it's likely not anything design specific aspect of the 200-series. It's basically what happens when the fuel gets hot enough, and atmospheric pressure low enough, ALONG WITH the formulation of the specific fuel that may lower its boiling point. Ethanol has been known to significantly decrease (10 degress +) the boiling point of fuels. I suspect it's the advent of more ethanol content fuels.

In regards to weak caps and relief valves... I'm not so sure it's something to be resolved. These relief valves are for safety. Too much pressure in a closed vessel starts to begin sounding like a bomb. The more pressure, the more boom, if there were to be ignition. I'm not so comfortable with vapors pouring out either as that brings the fuel closer to more potential ignition sources.

Then again, not sure I've ever read about any specific scenario of gas vapors off road resulting in a conflagration?

The concentration of ethanol is an interesting point since it's become exceedingly difficult to find ethanol free gas. I use this map (Pure-Gas.org : Map of Ethanol-Free Gas Stations in the U.S. and Canada) to find stations near me, and there are basically none that are anywhere near my house or office. Some of them don't have retail locations, so I use street view to make sure I can actually purchase gas there. I've seen the list dwindle in the last couple years which is very frustrating since I try as hard as possible to put ethanol free in my motorcycles. In fact, Ducati gas tanks have horrible swelling/expanding issues that occur with ethanol fuel, and there was a huge class action lawsuit years ago to replace the affected tanks and get them coated on the inside to hopefully prevent it from happening again. Ducati isn't replacing them any longer, so buying one used you have to be very careful to get one without swelling or you won't be able to put the gas tank back in place after removing it.
 
My biggest issue with the fuel smells and issues is that I've been driving the same routes and trails in Colorado and Utah for about 16 years, and I've never had any fuel smell issues with any vehicle other than the 200. I've driven all kinds of Toyotas and Jeeps in the same elevation and weather and trails without the issues, so I don't think it has as much to do with the environmental issues as much as it has to do with the 200 itself and its fuel or emissions setup.

FWIW I decided to try a new gas cap on mine, and the part number has changed recently for the 200 and appears a bit different than the old one. No issues yet with the new cap with 3 days in the mountains, so perhaps that was the culprit.

Worth a try. New part #? Thanks.

edit: Looks like this is the part number, 77300-53020,
listed for the 2017 Land Cruiser.
Filler Cap - Toyota (77300-53020)

And here's the old part, 77300-06040.
Toyota Land Cruiser (2006-2014) OEM Genuine GAS CAP 77300-06040 | eBay

Out of curiosity I purchased both gas caps from a Toyota dealer for sake of comparison - old part (77300-06040) on the left and new part (77300-53020) on the right:

LC200GasCaps_15AUG17_zpsenx3tnzq.jpg


They appear identical except for the change from up to E10 ghas on the old cap to up to E15 gas on the new cap. An interesting difference in that newer Cruisers can handle E15, but nothing to indicate any other differences. Not unreasonable to suspect that this difference was enough to require a new part number.

Of course, just as it is not possible to discern the pressure rating of a radiator cap just by looking at it, I can see no difference in the pressure spring between the old cap and the new cap. This doesn't mean there isn't a difference, but they appear identical.

I have no idea what the "Circle J" next to the CEL symbol on the old cap and the "Circle S" on the new cap mean ...

Just FYI.

HTH
 
Out of curiosity I purchased both gas caps from a Toyota dealer for sake of comparison - old part (77300-06040) on the left and new part (77300-53020) on the right:

LC200GasCaps_15AUG17_zpsenx3tnzq.jpg


They appear identical except for the change from up to E10 ghas on the old cap to up to E15 gas on the new cap. An interesting difference in that newer Cruisers can handle E15, but nothing to indicate any other differences. Not unreasonable to suspect that this difference was enough to require a new part number.

Of course, just as it is not possible to discern the pressure rating of a radiator cap just by looking at it, I can see no difference in the pressure spring between the old cap and the new cap. This doesn't mean there isn't a difference, but they appear identical.

I have no idea what the "Circle J" next to the CEL symbol on the old cap and the "Circle S" on the new cap mean ...

Just FYI.

HTH

My cap definitely wasn't giving me the last "click" so they are a wear product, I guess. After swapping caps I'm not getting the CELs for leaking evaporate but it's only been one day.
 
My cap definitely wasn't giving me the last "click" so they are a wear product, I guess. After swapping caps I'm not getting the CELs for leaking evaporate but it's only been one day.

Ya @TonyP ... Funny you mention that, because yesterday I picked up another code reader...as my truck threw codes again yesterday morning...TEN codes, to be exact! -And all 10 were related to the evap filter reporting a leak. And...I also noticed that my "click" on my gas cap feels iffy at best. I'm betting that's all it is. Interestingly, the codes only seem to register after sitting over-night. So maybe the heating/cooling vacuum/pressure thing is being picked up as a leak...? Gonna order a new cap and see. Meanwhile, clearing the codes is easy, and everything operates as normal afterward...
 

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