100 Caught fire & gas tank venting concerns

[mcewan13]

I just took a couple of hours to read through this thread. I have experienced this issue in both of my LC100s. On the lower milage one (135k), it happens semi-frequently. It happens at high elevations, rolling trails at low speeds, and highway speeds on hot days. It has even happened at sea level in early March (low 70s) while idling in stop and go traffic while crossing the MX/US border at Mexicali. I'm planning on checking the CC and associated valves first, but will likely be looking at shielding heat issues by cats (and possibly muffler). I have added a Magnaflow muffler and Dissent skids so I'm wondering if either / both of those issues have contributed to heat retention.

 

[2001LC]

Experiencing in both 03LC may be revealing clues in itself. I do think your EVAP approach is one they may both need. But make sure you get basics inline also.

First, you have been cleaning your radiators (all 3) fins right!

Radiator fins need cleaning! Alert Alert Alert

I've a 06LC w/192K I just bought. In reading history I found PO complained of engine temp raising when both front and rear AC on. Toyota Dealership diagnosed with clogged radiator fins. Recommended new OEM radiator, $600 for the US spec Radaitor plus coolant and labor. They should have added...

forum.ih8mud.com

In this thread the fuel boiling issues been kicked around a lot. There are different clues pointing to EVAP system. But most just need a good coolant service and a tune. It is looking like some will benefit from an EVAP system service as well. Seems more so, in the 03-07, when CC was moved to the rear.

Gas tank building excessive pressure & fuel smell. Dangerous for sure! Why does this happen?

IMO, absolutely a hazard and should not be opened. Let the safety relief do it's thing (IE keep it closed). I understand the urge to vent it quickly, but best to just let it vent and if you've got liquid misting out prepare any onboard extinguisher you have. Mine vents under the hood from the...

forum.ih8mud.com

 

[PIPO]

It started happening to mine on long trips (one hour or more). This last trip, I half turned the cap about that thing was venting for a good 6 mins…that’s a long time.

 

[Rebele92]

That is my basic understanding as well - the cap is supposed to allow air to enter under vacuum conditions (night time, when the fuel cools off), but if the tank develops pressure, the pressure is supposed to exit through a valve and move to the charcoal canister where the vapors will eventually be aspirated with air for combustion. So is it the valve on the tank that is causing the pressure to build up to problematic pressures?

Bingo

 

[2001LC]

Thinking out loud:

If Charcoal Canister (CC) saturated (spent). Then it's ability to hold or allow vapor to pass through, is reduce or even stopped except under very high pressure.

These spent CC are heavier than a new CC, as charcoal within is saturated with fuel. Old fuel in these CC. Tend to have a old fuel smell. Like fuel sitting in some old fuel tank for years. Often, we can smell this, while CC still in vehicle.

As we see and hear, vapors & hissing from gas tank cap area. This is as fuel pressure builds in the fuel tank, rather than equalizing by vent. As pressure increases, it creates heat. Heat, result in expansion, creating more pressure. As we increase in altitude, barometric pressure decreases. Thus external pressure on tank decreases. High pressure moves to low pressure. Fuel start to boil, pressure becomes dangerously high in fuel tank, wanting out. As we climb in altitude, boil point temp decreases.

CC under normal operating condition, last a very long time. The million mile Toyota Tundra, still had the factory installed (as I recall). I know of 2000LX w/400K miles, with factory installed CC still working.

So why are some CC being spent/damaged, sooner rather than later. First and foremost; raw fuel entering them. How does this happen:
A) Overfilled fuel tank in the 03-07.

1. Adding fuel, after auto shut-off of fueling pump handle. 2003-up OM, warns against this. Doing so can flood the CC.
2. Fueling on hot day, with cold fuel. Fuel heats to ambient temp, expanding in tank.
3. Engine & transmission running hotter than normal on hot days. Radiant heat from engine, CATs & transmission, asphalt along with high ambient temp. Heating fuel as it returns to tank and in tank, expanding fuel.

What to do:

1. First never overfill.
2. On hot days. Either don't fill up, to full. Or drive, after fueling to reduce fuel level. Giving room, for expansion in tank.
3. Service coolant system is number one. In getting engine operating temp to normal. Making sure all 3 radiators free of debris (clean radiator fins). Clogged Radiator fins, can't transfer heat efficiently away from coolant. These clogged fins, result in excessive operating temp of engine and transmission. W also need to, tune engine and flush transmission.

If a fuel boiling event, has happen. You can bet, CC damaged. If so, it needs replacing. But first, we must address why and correct the cause. Or we risk, damaging another CC.

 

[Hugh Heifer]

I want to reiterate that I had over pressure issues and a terrible gas smell both inside and outside of the truck. I got a new gas cap and all was solved.
I consider myself lucky based on all I have read here but if you have any issues, that is a cheap part that does need refreshing from time to time.

 

[Eyedaho]

I want to reiterate that I had over pressure issues and a terrible gas smell both inside and outside of the truck. I got a new gas cap and all was solved.
I consider myself lucky based on all I have read here but if you have any issues, that is a cheap part that does need refreshing from time to time.

I also experienced a strong fuel smell for a few weeks and solved it with a new gas cap. I believe that issue was decoupled from the fuel boiling issue in very hot weather that I have experienced. My fuel smell would occur with the vehicle parked in hot weather.

 

[PabloCruise]

Thinking out loud:

If Charcoal Canister (CC) saturated (spent). Then it's ability to hold or allow vapor to pass through, is reduce or even stopped expect under very high pressure.

These spent CC are heavier than a new CC, as charcoal within is saturated with fuel. Old fuel in these CC. Tend to have a old fuel smell. Like fuel sitting in some old fuel tank for years. Often, we can smell this, while CC still in vehicle.

As we see and hear, vapors & hissing from gas tank cap area. This is fuel pressure builds in the fuel tank, rather than equalizing by vent. As pressure increases, it creates heat. Heat, result in expansion, creating more pressure. As we increase in altitude, barometric pressure decreases. Thus external pressure on tank decreases. High pressure moves to low pressure. Fuel start to boil, pressure becomes dangerously high in fuel tank, wanting out. As we climb in altitude, boil point temp decreases.

CC under normal opening condition, last a very long time. The million mile Toyota Tundra, still had the factory installed (as I recall). I know of an 00LX w/400K miles, with factory installed CC still working.

So why are some CC being spent/damaged, sooner rather than later. First and foremost; raw fuel entering them. How does this happen:
A) Over filled fuel tank.

1. Adding fuel, after auto shut-off of fueling pump handle. 2003-up OM, warns against this. Doing so can flood the CC.
2. Fueling on hot day, with cold fuel. Fuel heats to ambient temp, expanding in tank.
3. Engine & transmission running hotter than normal on hot days. Radiant heat from engine, CATs & transmission, asphalt along with high ambient temp. Heating fuel as it returns to tank and in tank, expanding fuel.

What to do:

1. First never overfill.
2. On hot days. Either don't fill up, to full. Or drive, after fueling to reduce fuel level. Giving room for expansion in tank.
3. Service coolant system is number one. In getting engine operating temp to normal. Making sure all 3 radiators free of debris (clean radiator fins). Clogged Radiator fins, cann't transfer heat efficiently away from coolant. These clogged fins, result in excessive operating temp of engine and transmission. W also need to, tune engine and flush transmission.

If a fuel boiling event, has happen. You can bet, CC damaged. If so, it needs replacing. But first, we must address why and correct. Or we risk, damaging another CC.

Do you know if people successfully opening the CC and refreshing the activated charcoal media?
I have heard of people doing this with charcoal for an aquarium.

 

[Live to Ski]

Do you know if people successfully opening the CC and refreshing the activated charcoal media?
I have heard of people doing this with charcoal for an aquarium.

there is an extensive thread on this. You will have to use the search function to dig it up.

 

[2001LC]

Do you know if people successfully opening the CC and refreshing the activated charcoal media?
I have heard of people doing this with charcoal for an aquarium.

I've not, I just use new OEM. But some in mud have. But IIRC, someone stated, it's not aquarium charcoal.

 

[Joe470]

I've not, I just use new OEM. But some in mud have. But IIRC, someone stated, it's not aquarium charcoal.

Did mine yesterday, straight from Petco

 

[J1000]

Whoever said that pressure in the EVAP leads to boiling is just flat out wrong. Pressure stops boiling. For example your engine cooling system is pressurized which raises the boiling point which is why coolant can exceed 212F without boiling. Water boils in space at sub-zero temperatures, because the pressure is low.

So again, we want the tank to remain pressurized and we want the temperature to be as low as possible.

I replaced the charcoal in my canister but it started leaking after a year or so. Had trouble getting the plastic-weld to not dissolve from the gas fumes. If I tried again I would use a hole-saw instead of cutting off the end. Also I would try really welding plastic vs. using permatex stuff.

Really though, the EVAP canister from a Camry or Solara or even Scions from the 00s is the same as 100 series. Plug and play and half price. ('03+ only)

Lastly, if you want to try and dry out your EVAP canister you can run the hose directly to the vacuum port on the engine and bypass the switching valve for a few thousand miles. It may throw a CEL but it will dry out the canister.

 

[socalmtbiker]

I last posted in September 2020 about this issue. No problems since. This time a drive from San Diego to bishop on all freeway. Temp 90-105s, elevation 4K, 7hr of driving, towing oof road trailer and loaded.
My first refuel no issues. I did notice pressure when opening the gas cap but not entirely unusual.
Second refueling, I observed hissing. No fumes. No expelling of gas but did hear gurgling when i
Removed the cap. I was at less than a quarter tank of gas. And filled up.
When I arrived to bishop and stopped the rig was venting significantly and gas fumes were strong. (No smell the other times.) I didn’t have my tablet to monitor actual engine/trans temps. Outside Temp was 100.
Disappointing to have it occur on my drive yesterday. Was planning to hit some trails. Not sure what is the actual root cause. I’ll get a new gas cap firstly.
I was going to make skid plates but I’m seconds guessing with this issue.
2005 lx 161k miles

 

[Live to Ski]

noted.

new gas cap solved that for me. 4 to 5 years no issues. 'course the temp rarly rise above 85 here in coastal SoCal.

big trip coming up to boulder in mid august (hotest time of year). No off road. trans great basin. will report back w. torque OBD data.

 

[OwnerCS]

As our 100s become members of the "Quarter Century Club", keeping our fuel systems serviced helps them run like new and climb to extreme heights without issue. I got into years ago with an approach named "Midlife Maintenance Refresh" that was more necessity with early fuel injection systems. Fuel systems items that I have replaced on the 02 model in order of need.

1) Flexible fuel tank hose (the one that looks like a radiator hose) became brittle from age and started leaking when the tank was more than 3/4 full.

2) Fuel tank vents to the Evap system. Replaced at the same time as #1.

3) Fuel pump. I happened to have one of the rare Denso saved so I replaced it. I carry spare fuel pumps that work for both 80 and 100 series. Also, carried is an 80 series fusible link. I wheel with a bunch of 80 and 100 series owners. You never know when a fuel pump might bite the dust on a trail.

4) Fuel rail pressure regulator and fuel damper. I've seen plenty of issues from old rubber or seals in those cause problems atter 20 years. No time to deal with that on a trip at high altitudes.

5) Cleaned and tested injectors that include new o-rings. Again old rubber in a fuel system is dangerous.

6) All rubber hoses in the fuel delivery system were replaced.

7) Fuel Filter - usually soon after purchasing an old vehicle.

8) Fuel cap (and radiator cap) -- one of the first things that I replace when purchasing an old vehicle.

When I'm done, they run like new for years. I can't remember any high altitude problems in the San Juan Mountains of Colorado.

 

[2001LC]

We must keep coolant system, engine and AT running as design and within their op temp. "properly maintained"

If all as it should be, and still getting excessive fuel tank pressure. Charcoal Canister (CC), is last on the list. Last, since we don't want to damage the replacement CC.

Note:
Some fuel tank pressure is normal. (Read your OM)
If using CAT theft Shield or bell pan. They can create a canal that direct hot air on fuel system components. Consider shield fuel lines from extra heat and divert hot air flow away from fuel tank, that comes from CATs.

 

[OwnerCS]

We must keep coolant system, engine and AT running as design and within their op temp. "properly maintained"

If all as it should be, and still getting excessive fuel tank pressure. Charcoal Canister (CC), is last on the list. Last, since we don't want to damage the replacement CC.

Note:
Some fuel tank pressure is normal. (Read your OM)
If using CAT theft Shield or bell pan. They can create a canal that direct hot air on fuel system components. Consider shield fuel lines from extra heat and divert hot air flow away from fuel tank, that comes from CATs.

Great point! In the mountains, I drive in 4LO as much as possible to keep the transmission and engine coolant temps as low as possible. Usually, my engine and transmission temperatures run lower on mountain roads compared to when I'm driving on the interstate.

 

[2001LC]

As our 100s become members of the "Quarter Century Club", keeping our fuel systems serviced helps them run like new and climb to extreme heights without issue. I got into years ago with an approach named "Midlife Maintenance Refresh" that was more necessity with early fuel injection systems. Fuel systems items that I have replaced on the 02 model in order of need.

1) Flexible fuel tank hose (the one that looks like a radiator hose) became brittle from age and started leaking when the tank was more than 3/4 full.

2) Fuel tank vents to the Evap system. Replaced at the same time as #1.

3) Fuel pump. I happened to have one of the rare Denso saved so I replaced it. I carry spare fuel pumps that work for both 80 and 100 series. Also, carried is an 80 series fusible link. I wheel with a bunch of 80 and 100 series owners. You never know when a fuel pump might bite the dust on a trail.

4) Fuel rail pressure regulator and fuel damper. I've seen plenty of issues from old rubber or seals in those cause problems atter 20 years. No time to deal with that on a trip at high altitudes.

5) Cleaned and tested injectors that include new o-rings. Again old rubber in a fuel system is dangerous.

6) All rubber hoses in the fuel delivery system were replaced.

7) Fuel Filter - usually soon after purchasing an old vehicle.

8) Fuel cap (and radiator cap) -- one of the first things that I replace when purchasing an old vehicle.

When I'm done, they run like new for years. I can't remember any high altitude problems in the San Juan Mountains of Colorado.

Some here in mud like J2000, will say all 100 series boil fuel. Your's is just one more example of what I say: "They don't", when properly maintained.

 

[Brandon Ryder]

4) Fuel rail pressure regulator and fuel damper. I've seen plenty of issues from old rubber or seals in those cause problems atter 20 years. No time to deal with that on a trip at high altitudes.

I haven't seen much attention to these parts. I wonder what your experience is with these and what are the symptoms of them failing?

Wondering if a fuel pressure regulator or damper could be causing the engine to run too lean, causing engine to run hot and possibly heating the fuel that returns to the tank. Just a WAG. What were your experiences?