100 Caught fire & gas tank venting concerns

[Julian Stead]

If this happened to myself, I would modify a spare cap to fit when going up to altitude to allow the tank to vent to atmosphere so no pressure difference is gained. I would try and drill and fit a pipe through it. Fuel Tanks used to vent to open air before emmision laws become more strict. Just put your original cap back on and clear fault codes when back to normal driving.

I spoke to a my Old collegue about this who used to be a master tech with myself and we both agreed that neither of us got trained on the system and we never once had a fault in 10 years with the system. Laws over here are not as strict as the US, but we did have a charcoal canister up in the wheel tub, but I never saw it, this had a pipe to the tank and a pipe to the inlet manifold with a pump inline, when the car went to idle the pump would operate to empty the charcoal canister, that was all that was in the system, no sensors. The only complaint we used to get was the pump would tick like a loud injector at idle and annoy the customers.

 

[PabloCruise]

Rotate your phone 90 degrees. Sig lines show up when I hold my iPhone sideways.

Sum bitch... Learn something new every day!

 

[Live to Ski]

Gotta be complicated, but how about a relocation kit for the "under spare" location rigs.

 

[abuck99]

Going to suggest the minute you modify the EVAP system, any liability would likely be assumed by you and Toyota is off the hook.

 

[PabloCruise]

I'd like to add my experience to this discussion and hopefully help the collective wisdom.
01 LX with 16 gallon gravity fed aux tank (no transfer pump).

(I am going to be brief...its late and I am tired...not being snippy).

The gas cap is most definitely intended to be a one way valve, for letting air in and not vapor out (unfortunately imo).
Charcoal canister in the 01 is up front.

My understanding of the CC operation is as follows:
When engine is not running, vapors vent from the tank to the canister and then through the charcoal to remove the odor and then out into the atmosphere in the left hand frame rail! Follow a hose from the canister to see this.
When the engine is running, vapors vent to the canister and then get sucked into the manifold from the canister due to the low pressure in the air intake manifold. A combination of valves on the canister choose the path to vent.

Pressure builds up in the tank due to altitude changes (up) and even temperature increases. The pressure can't vent through the canister if the canister has been flooded with gas (liquid form). Two things can happen here. Gas (liquid again) carries charcoal fragments through the filters into the valves that operate the venting options for the canister. Or, gas can leave gum/residue on those same valves. The effect is the same, the valves get stuck in the wrong positions. Also having liquid gas in the evap. line from your gas tank to the canister or liquid gas in the canister plug it up - preventing the tank from venting.

Gas can get into the evap line and/or the canister during wheeling if the tank is full-ish, and your cruiser is going up/down hill - very steeply - which interestingly enough happens a lot when you go wheeling....or even driving in the mountains.

In my case, before I realized this...I exacerbated the issue, because of my aux tank set up. The Front Runner aux tank sits above the spare tire in the back....and its gas fill line is higher than the top of the main tank. This means that if the aux tank is full, there is no air gap in the top of the main tank which means its really easy to flood the evap line to the canister and the canister itself! I have since replaced my canister with a cheap one here. I really suspect the FR aux tank is intended for diesel and not petrol...but hey - whatever.

My solution was to move my evap line from the main tank to the top of the filler neck so that its never under the gas fill line of either tank - even on an incline.

Some ideas for trail-only solutions.
When I was debugging my issue, for a while I bypassed my canister completely and hooked the evap line from the tanks directly to the frame rail vent line. Sometimes there was an odor when stationary...but not bad. I will say that the engine seemed to run much better too, it was awesome. So an option for those mountainous trail days is to take along a little fitting and temporarily connect your evap line to the vent line so that you tank can breathe more freely. Yes, you may get a CEL, but it really means nothing and is easy clearled with your *Gauge. I think venting a little like that is low risk, and much lower risk than driving around withe a pressurized tank. ( I have heard mine pop and creak even when under pressure).

Of course you can also not fill up so full so that driving up/down hill doesn't flood your evap line/canister....but for offroad mpg this seriously can reduce your range.

I do think that if your canister has been flooded, even just a few times, it may already be clogged ...

HTH...

Good stuff here, as is your post on the charcoal canister service.

This is partially helpful, but I wonder if the FSM has some descriptions of how the purge is activated, and how the air inlet and air drain hose work, and how the vapor pressure sensor works? I asked in your other post if you could see how the charcoal had been damaged by the liquid fuel getting up there?

 

[PabloCruise]

2001 LC here. You can find a RTH thread here while on my way thru Black Gap in Big Bend. For anyone here saying to let the system purge out, it's one of those things that if it hasn't happened to you its hard to grasp the amount of pressure built up. There is no way the system will manage it. It's overwhelmed at the point of smelling gas inside the cab. It's in my opinion a design flaw regardless of the changes in fuel and Toyota needs to do the right thing. Unfortunately until someone dies and there is a big lawsuit it won't happen. The pressure is so high that it can take over 30 mins for gas to stop rushing out of the cap and sometimes even fuel. It's extremely dangerous and borderline criminal to have no solution for it from Toyota. There has been less dangerous recalls made by other manufacturers. I can't figure out why this one is not getting any attention. Hope this thread works as a reference for someone in the future as proof there is a big flaw that was not taken seriously.

Do we know if anyone has tried to contact Toyota about these issues?

 

[4gotalot]

My 2011 200 series has this this problem a couple of times with fuel tank at 50-75%, 65 deg f, above 6k feet, but only on trails when the fuel is shaken not stirred. Bad enough smell in the cab and down wind that I have to park down wind when we all stop for a break and still for another 20 min+.

I picked up a new OEM fuel cap but will not install until I have vapor problem again to ops ck at time of fault. No fuel leaks in the sys and would have been easy to spot with all of the trail dust.

I agree that there is something wrong with the evap system. Design flaw or dirty ck vlv is still to be found. I'm hope Mr. T has payed its engineers well but I'm sure the legal department gets paid more.

Does any one know the reporting system well enough to help us out so myself and others can make a report some were so they know the extent of this problem. Dealer service center was the first step. I am not comparing this to a floor mat not staying in place but a cloud of raw fuel vapor venting for 20 min. We should be asking Mr. T or others, "whats wrong with this picture"?

Any ideas as to were to go from here?

 

[sean2202]

@4gotalot you could contact corporate Toyota state your case and open a claim. Unlikely they will do anything but at least you have done your due diligence.

Anyone know if the individual with the fire reported it to police and the NHTSA? I read through all years of 100 cruisers a few years back and didn't see anything on vehicle fires.

Filling up my 2000 LC(181k) at sea level the other day windows up kids in the car. They started banging on the windows crying "it stinks in here like gas" I thought they were just being babies...now I'm concerned.

 

[suprarx7nut]

Good stuff here, as is your post on the charcoal canister service.

This is partially helpful, but I wonder if the FSM has some descriptions of how the purge is activated, and how the air inlet and air drain hose work, and how the vapor pressure sensor works? I asked in your other post if you could see how the charcoal had been damaged by the liquid fuel getting up there?

Looking here, it would seem the VSV must fail to open AND the air inlet line AND the air drain line would need to be blocked to disallow venting with pressure in the tank.

Is there a controlled valve at the charcoal canister that's not called out in that drawing? It looks like those air lines are segregated from the canister cavity.

 

[Atx100]

Hmmm....a couple months back, I was wheeling with some friends at Hidden Falls, Tx. It was about 90 degrees that day and while on a trail started to smell a strong smell of gasoline and could hear some bubbling like noises. One of my buddy's came over and told me to vent the gas tank because it was "boiling". I'd have never heard of this prior, but we vented it for a couple minutes and everything seemed fine from then on. That's the only time that has ever happened and there was no high elevation involved, I'm wondering if this is the same or similar issue in terms of venting?

 

[savirc]

Do we know if anyone has tried to contact Toyota about these issues?

Yes, I contacted them and so have other folks. Case has to be opened with the government I was told.

 

[PabloCruise]

Yes, I contacted them and so have other folks. Case has to be opened with the government I was told.

So the complaints must be registered with NHTSA?

 

[PabloCruise]

Looking here, it would seem the VSV must fail to open AND the air inlet line AND the air drain line would need to be blocked to disallow venting with pressure in the tank.

Is there a controlled valve at the charcoal canister that's not called out in that drawing? It looks like those air lines are segregated from the canister cavity.

I wish I knew. Sometimes the description of System Operation are very useful. I do not have an FSM, but can look at a friend's later this week...

 

[Julian Stead]

These are the test procedures, all you need is a Mitivac.

 

[TheForger]

This happened to me on my way up to Imogene in August. Very dangerous stuff, luckily we didn't have any accidents. "I don't think we should do this" are some very valuable words to live by.

 

[geanes]

This happened to me on my way up to Imogene in August. Very dangerous stuff, luckily we didn't have any accidents. "I don't think we should do this" are some very valuable words to live by.

At least is was just cascading fuel out. I've seen them where they spew violently a near vaporized fuel for quite some time. Crazy dangerous. When mine boiled at the top of Imogene, we immediately started down. Once below 12.5k all was well and the boiling stopped. I was at 1/2 tank at the start of Imogene. The only places mine boiled loud enough to hear was at the top of Imogene and Mosquito (both over 13k). By loud enough to hear, I mean that people walking around at the top of Imogene were asking where the "hissing" sound was coming from....THAT loud. When we got down to Ouray, I noticed an gas slick on the fender below the door. The cap had actually let some gas go by. This was a new OEM cap that I bought with the vehicle in March of this year.

 

[Julian Stead]

This happened to me on my way up to Imogene in August. Very dangerous stuff, luckily we didn't have any accidents. "I don't think we should do this" are some very valuable words to live by.

To me that looks like the fuel has expanded due to heat, it is just pouring out as if there is to much in the tank.

 

[TheForger]

At least is was just cascading fuel out. I've seen them where they spew violently a near vaporized fuel for quite some time. Crazy dangerous. When mine boiled at the top of Imogene, we immediately started down. Once below 12.5k all was well and the boiling stopped. I was at 1/2 tank at the start of Imogene. The only places mine boiled loud enough to hear was at the top of Imogene and Mosquito (both over 13k). By loud enough to hear, I mean that people walking around at the top of Imogene were asking where the "hissing" sound was coming from....THAT loud. When we got down to Ouray, I noticed an gas slick on the fender below the door. The cap had actually let some gas go by. This was a new OEM cap that I bought with the vehicle in March of this year.

To me that looks like the fuel has expanded due to heat, it is just pouring out as if there is to much in the tank.

Guess I should've specified, but originally when I took the gas cap off it made a very violent hissing sound but there was no liquid at that point. I mean like almost a crude whistling noise and people who were stopped around me were wondering what it was thinking something was wrong with their own vehicles. I remember one guy checked his tires thinking one of them was punctured because it sounded very similar. I walked away for 5min to talk to some guys and when I came back it had gone from releasing vapor to gas boiling out of the tank. As you can see in the video it dissolved the plastidip on the side moulding. I was at about 3/5 of a tank at that point.

 

[Julian Stead]

I found a article on vapor lock, it talks about the boiling of gasoline at altidude, It refers to heat, and the lower pressure being the cause. It would be good to find out what the fuel tank temp gets to at altitude. The tank gets recycled fuel, it is close to the exhaust, there is less cooling effect in the air due to altitude, the engine will be working harder and moving slowly whilst wheeling. It all adds up. Just take some readings with a infra red thermometer.

I always thought my tank had a negative pressure and not a positive, as it seems to suck and not blow.

Any chemistry experts on here that could shed some light into why the gasoline gets to boiling point and what can be done to reduce the effects.

 

[abuck99]

What effect does the fuel tank skid plate have on heat retention?