100 Caught fire & gas tank venting concerns (1 Viewer)

[1meancruiser]

Also, in concluding what i believe to be the solution to the vapor lock/heating of fuel (outside of the EVAP charcoal filter and tank vent TSB replacements), i just realized the person who starting this thread, skidoo, may have a case against Toyota!

Giving this its own thread as it is in What have you done to your 100. Link to it here
What have you done to your 100 Series this week?
It is not clear how the fire started, but hearing from the folks that were there, it escalated quickly.

We may want to discuss fuel tank venting, as owner was venting his tank about time fire started, but it may not be the cause. Those of us that have taken our 100s to high elevations have encountered the gas smell as it seems venting has trouble keeping up with elevation change. At 100s in the Hills (its all above 9000 ft) we are told not to fill tank all the way to mitigate the issue. A number of folk there needed to vented their tanks and saw the amount of pressure build up. Venting in these cases needs to be done slowly and carefully.

The incident above was at Cerro Gordo, CA, elevation 9000ft, mid 70s temperature. May have been due to venting, or some other condition.

[The following added 8/25/2018]

More data on this issue. Ethanol smoking gun?? I just spent a week in Silverton, CO running the high passes. Last year a week earlier I was in Silverton for 100s in the Hills. Weather conditions were the same as last year, and ran the same trails this year. This area has to be the worst case scenario for gas tank venting as Silverton is 9300 feet in elevation and you are going up to passes as high as 13,113 feet from there.

Last year I ran gas with ethanol and had high pressure venting when opening cap at the passes. Only filling to ¾ of a tank helped but did not eliminate the pressure venting. This issue seemed to be common with the other rigs on the trail.

This year 100s in the Hills was too early for me to attend, so planned my own trip with a friend and his 80 series. This year we found a small station in town that offered ethanol free premium gas and we used only that for both our rigs. I had no venting pressure at all when opening gas cap on the high passes this year. After the second day I was filling the tank to full and no issues. My 100 is the same, no changes since last year. My friend’s 80 has had the venting issue in the past but running ethanol free gas here he also had no venting pressure when opening gas cap on high passes.

My belief is that its the ethanol based fuels causing this issue, but run your own tests, see what you find.
I see the labels on gas pumps say "May contain up to 10% ethanol" wonder how much ethanol content actually varies station to station and over seasons. This might explain why folks see different behavior.

 

[MongooseGA]

Happy to have this thread to read through. I occasionally smelled fuel in my last 100, and now I get it after I've been sitting for a while in my current one. It's prevalent enough that passengers have commented on it. The heat shield idea looks great and super simple. I can fab up a break to bend something that length pretty easily (bench vice won't really cut it). Do you think self tapping screws will bite into the surface behind the 90 degree bend?

 

[gatormark91]

If the vacuum switching valves (VSVs) work (both of them) and the charcoal canister is good, the vapors go out of the tank, through the canister, manifold vacuum pulls them into the intake manifold and they get burned up. That's it. When the truck is stopped, the VSVs close, so the vapors don't get out to atmosphere.

It's actually a really simple system. If you are getting pressure in your tank, one of those three parts is wrong. The VSVs will mostly work, but if they are a little off, they can stick. Lots of people replacing their charcoal canisters, but I bet they don't replace the VSV on the intake manifold. Non-ethanol fuel is going to help, but it is just disguising an issue with one of those parts for most people, IMHO. I refilled my canister, replaced my purge VSV, and problem gone.

 

[1meancruiser]

Yes, i think they'll bite. The heat shield on the LC is 22-24 gauge steel so self tapping screws should work fine...

Happy to have this thread to read through. I occasionally smelled fuel in my last 100, and now I get it after I've been sitting for a while in my current one. It's prevalent enough that passengers have commented on it. The heat shield idea looks great and super simple. I can fab up a break to bend something that length pretty easily (bench vice won't really cut it). Do you think self tapping screws will bite into the surface behind the 90 degree bend?

 

[1meancruiser]

I did the same, possibly with the exception of the valve on the intake manifold (I have to check). The LC ran fine but i still smelled gas. My only thought is, i don't know if those valves can purge the tank of the fumes to keep up with the rate of the constant heating of the fuel going into the tank.

If the vacuum switching valves (VSVs) work (both of them) and the charcoal canister is good, the vapors go out of the tank, through the canister, manifold vacuum pulls them into the intake manifold and they get burned up. That's it. When the truck is stopped, the VSVs close, so the vapors don't get out to atmosphere.

It's actually a really simple system. If you are getting pressure in your tank, one of those three parts is wrong. The VSVs will mostly work, but if they are a little off, they can stick. Lots of people replacing their charcoal canisters, but I bet they don't replace the VSV on the intake manifold. Non-ethanol fuel is going to help, but it is just disguising an issue with one of those parts for most people, IMHO. I refilled my canister, replaced my purge VSV, and problem gone.

 

[Skidoo]

IMHO. I refilled my canister, replaced my purge VSV, and problem gone.

gatormark91 When you were having the issue before replacing the parts was it all the time? Or was it only at high elevation 9000+ feet. Want to determine if we are talking about the same issue. I have no pressure in mine until I get above 9000 feet with E10 ethanol fuel. Long summer days at 110 degrees, no issues, so pretty sure my evap system is working. Non ethanol fuel no issue above 9000 feet.

 

[kickitrootdown]

I did the same, possibly with the exception of the valve on the intake manifold (I have to check). The LC ran fine but i still smelled gas. My only thought is, i don't know if those valves can purge the tank of the fumes to keep up with the rate of the constant heating of the fuel going into the tank.

I have done a LOT of reading about this issue because I simply couldn't understand how this was happening and it was driving me nuts, and these two comments really do a good job of summarizing the issues.

1.) In a perfect world (i.e., not a 20 year old truck with 200k+ miles), the purge system is able to adequately vent vapors from the gas tank.

2.) In the real world for most of us (i.e., a 20 year old truck with 200-300k miles), the purge system is fully operational but flawed and cannot be simply remedied even if the cost is not restrictive. Additionally, just knowing about the problem and its occurrence in highly limited scenarios reduces its impact greatly.

 

[gatormark91]

Yes, mine did it all the time. It was bad enough that it took the paint off near my fuel filter door. I live in Florida and run E10. Months of 95-100 degree weather.

The evap system is basically a controlled vacuum leak that sucks in fumes. If you fix all the parts, it will work fine. Your engine draws enough vacuum at idleidl pull all the fumes throught if the valves open all the way, the charcoal is not used up, and the evap hoses aren't all swollen shut with age It's $$$ to fix if you don't do your own work, though, which sucks. It cost me less than $200 to replace the valves and break open my canister and replace the charcoal . But my evap system is as good as factory new now. 100 degrees, no gas smell, no venting, not once since.

Additionally, when certain conditions are seen by the ECU, it will run an "LA4" test on the evap system. This is supposed to simulate idling in hot Los Angeles traffic at 4pm (hence LA4). In this self-test, it closets the purge valves and pressurizes the evap system to check it. It's just a guess, but I am thinking that folks with blockages or sticky valves aren't getting helped by this test either.

 

[bushdoctor]

I had this s*** happen to me the first time this past weekend while out in Utah wheeling with @perrobravo @Dan2722 . All I can say is...it SUCKS. I've been at high altitude before in several places, varying temperatures (low-high) but I cant recall how much gas fill I had in the tank by the time we went past 6K ft. I've vented the tank before but never this critical. This time, we gassed up, and after 20 minutes drive we were going up to 6K ft.

There was a STRONG smell of gas on the trail, so strong that my buddies thought they were leaking gas from their jerry's. Anyway, the smell was too intense and I decided to get out and check my status. Alas, Jerry and rotopax were dry but I heard a hiss in my fuel tank and it was all wet on the quarter panel and a 'cloud' of gas evap was visible. I decided to slowly open the cap and the further I opened the more gas spilled out. It was like the gas was boiling/bubbling. I remembered one of the guys with us on the trail smokes and reminded him not to even think about lighting a cig. It took quite a while for the venting to complete.

I have a video of the gas spilling out but here's a pic. The inside of my truck still smells of gasoline 5 days later - more so on the driver side quarter panel.

 

[savirc]

I had this s*** happen to me the first time this past weekend while out in Utah wheeling with @perrobravo @Dan2722 . All I can say is...it SUCKS. I've been at high altitude before in several places, varying temperatures (low-high) but I cant recall how much gas fill I had in the tank by the time we went past 6K ft. I've vented the tank before but never this critical. This time, we gassed up, and after 20 minutes drive we were going up to 6K ft.

There was a STRONG smell of gas on the trail, so strong that my buddies thought they were leaking gas from their jerry's. Anyway, the smell was too intense and I decided to get out and check my status. Alas, Jerry and rotopax were dry but I heard a hiss in my fuel tank and it was all wet on the quarter panel and a 'cloud' of gas evap was visible. I decided to slowly open the cap and the further I opened the more gas spilled out. It was like the gas was boiling/bubbling. I remembered one of the guys with us on the trail smokes and reminded him not to even think about lighting a cig. It took quite a while for the venting to complete.

I have a video of the gas spilling out but here's a pic. The inside of my truck still smells of gasoline 5 days later - more so on the driver side quarter panel.


View attachment 1821719

This happened to me in Big Bend in desert type of heat and on the trail with 3/4 full tank. I replaced the evap canister with OEM toyota and no problems since. I think I paid 500 dollars it was not a cheap part.

 

[bushdoctor]

This happened to me in Big Bend in desert type of heat and on the trail with 3/4 full tank. I replaced the evap canister with OEM toyota and no problems since. I think I paid 500 dollars it was not a cheap part.

Will look for the part #

 

[savirc]

Will look for the part #

Here is the part # and price from my invoice:

I did file a case BTW and everyone should try to do it, maybe one day they will do something:

 

[RiverRatMatt]

Towing our camper in our 2000 LX from ~2700ft to 7000ft this summer in >100 degree weather I noticed a fuel smell when stopped and could hear the pressure valve releasing. I stopped a couple times and pulled the gas cap off to let it vent, glad I did. I wonder if the LX is more susceptible to this because it uses premium fuel, which AFAIK includes alcohols as an octane booster.

 

[socalmtbiker]

I reported to Lexus for my lx. Since they couldn’t recreate it they disregarded it even when I called Lexus Usa. Try reporting here too. The more complaints the more they’ll realize there’s a real problem.
https://www-odi.nhtsa.dot.gov/VehicleComplaint/

Here is the part # and price from my invoice:

View attachment 1821743

I did file a case BTW and everyone should try to do it, maybe one day they will do something:

View attachment 1821741

 

[KraziAzn]

Towing our camper in our 2000 LX from ~2700ft to 7000ft this summer in >100 degree weather I noticed a fuel smell when stopped and could hear the pressure valve releasing. I stopped a couple times and pulled the gas cap off to let it vent, glad I did. I wonder if the LX is more susceptible to this because it uses premium fuel, which AFAIK includes alcohols as an octane booster.

LC uses premium fuel too. (at least that is what my gas cover says on my 2000 LC)

Also, the best practice is to leave the tank half full to reduce the pressure?

 

[kickitrootdown]

LC uses premium fuel too. (at least that is what my gas cover says on my 2000 LC)

Also, the best practice is to leave the tank half full to reduce the pressure?

From what I have researched, yes.

There are a bunch of different "fixes" that people have posted including replacing the gas cap, replacing the charcoal canisters, using ethanol-free fuel, etc, etc. For every one that "fixes" one truck, it doesn't fix another. I'll throw my own out there and add that my fuel sender was shorting out and my electrician was confident that sending a 12v current through the gas tank helped boil the gas. I've read that people drop a couple thousand trying to get at the root of the problem with the biggest "fixes" and get nowhere.

I have opted for keeping it simple - first, I had to replace the sender because it blew up my dashboard. Second, I got a new gas cap. Third, I found all of the local ethanol-free gas stations and have been using those. Fourth, when I'm going over the high Utah passes, I pull over every few thousand feet and open the gas cap to make sure. No issues crawling around the Uintas and Moab so far.

 

[KraziAzn]

From what I have researched, yes.

There are a bunch of different "fixes" that people have posted including replacing the gas cap, replacing the charcoal canisters, using ethanol-free fuel, etc, etc. For every one that "fixes" one truck, it doesn't fix another. I'll throw my own out there and add that my fuel sender was shorting out and my electrician was confident that sending a 12v current through the gas tank helped boil the gas. I've read that people drop a couple thousand trying to get at the root of the problem with the biggest "fixes" and get nowhere.

I have opted for keeping it simple - first, I had to replace the sender because it blew up my dashboard. Second, I got a new gas cap. Third, I found all of the local ethanol-free gas stations and have been using those. Fourth, when I'm going over the high Utah passes, I pull over every few thousand feet and open the gas cap to make sure. No issues crawling around the Uintas and Moab so far.

Good to know. When I was HIH8 my tank was half full, didn't have any issues with pressure. I'll be in Moab this Jan, I'll just keep the tank half full again. And vent the gas gap when needed.

 

[Skidoo]

Good to know. When I was HIH8 my tank was half full, didn't have any issues with pressure. I'll be in Moab this Jan, I'll just keep the tank half full again. And vent the gas gap when needed.

I have not had the issue on trails around Moab, even with a full tank, so it may not be something to worry about.

 

[gatormark91]

How to fix this for good... Replace the VSVs. Do the one on the engine first, since it is the most important and most likely one to be messed up. The VSV on the canister just exposes the pressure sensor to vacuum during the LA4 self-test cycle, if I remember right, and is less important in scavenging the fumes. Replace (or refill) the evap canister, replace the gas cap, and forget about it happening again. I did all the above (refilling the canister myself from MUD write-up), it cost me $150-$200. Done, no more issue.

Anything else is just bandaid suggestions from people who, IMHO, maybe don't entirely get how the evap system and its self-test function works in a 100 series. It's basically a controlled vacuum leak that sucks up the vapors from a sealed system and, surprisingly, most of its emissions work is done when the engine is actually off, storing the fumes from the tank. The VSVs over the years will not function as well as they should, or will stick, so they won't throw a code letting you know they are bad when the ECU runs the self-test on them, and the evap canister loses its efficiency in storing the fumes. Replace one part of the equation, and you get some relief, maybe, or none at all. Break out a vacuum gauge, Techstream, and the FSM and run through the factory evap tests and you'll see how this all actually works, right or wrong. Do the above fixes and you'll be perfectly fine for a long time.

The emissions bits wear out over (a long) time. It's not a warranty issue or recall safey issue, it's life with a vehicle with a body, engine, and transmission that will out-last most of its attached parts.

 

[savirc]

How to fix this for good... Replace the VSVs. Do the one on the engine first, since it is the most important and most likely one to be messed up. The VSV on the canister just exposes the pressure sensor to vacuum during the LA4 self-test cycle, if I remember right, and is less important in scavenging the fumes. Replace (or refill) the evap canister, replace the gas cap, and forget about it happening again. I did all the above (refilling the canister myself from MUD write-up), it cost me $150-$200. Done, no more issue.

Anything else is just bandaid suggestions from people who, IMHO, maybe don't entirely get how the evap system and its self-test function works in a 100 series. It's basically a controlled vacuum leak that sucks up the vapors from a sealed system and, surprisingly, most of its emissions work is done when the engine is actually off, storing the fumes from the tank. The VSVs over the years will not function as well as they should, or will stick, so they won't throw a code letting you know they are bad when the ECU runs the self-test on them, and the evap canister loses its efficiency in storing the fumes. Replace one part of the equation, and you get some relief, maybe, or none at all. Break out a vacuum gauge, Techstream, and the FSM and run through the factory evap tests and you'll see how this all actually works, right or wrong. Do the above fixes and you'll be perfectly fine for a long time.

The emissions bits wear out over (a long) time. It's not a warranty issue or recall safey issue, it's life with a vehicle with a body, engine, and transmission that will out-last most of its attached parts.

I disagree. My truck had less than 80k miles on it when this happened, and I also replaced the VSV and bench tested the old one manually actuating it and the old one was still good. I also studied the diagram with the service manual in hand. This is also an issue with the 200 (look into it) Regardless... writing this off to use and wear and not have it addressed by the manufacturer as a shortcoming compared to other manufacturers having zero issues doesn't make any sense to me. I've driven many miles at many altitudes and temperatures with other vehicles and original canister. Things don't improve if you don't report, this Toyota item obviously could be improved on... gas fumes in a cab is never something to be proud of as a car maker.