Gas/Fuel vapors/fumes visible from gas door (1 Viewer)

TheGrrrrr

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Has anyone with an aux tank tried filling the main tank when the main tank is boiling? That should cool it down and maybe stop the boiling??? Of course that isn't a solution but just a way to test the theory.


@TheGrrrrr, maybe you could just run the return fuel line through your shower heater on your roof rack and get both cool fuel and hot water...

I like the logic on the aux tank, but I think someone tried that and found that the transfer pump will immediately disengage because of the pressure levels in the main tank. If that could be overcome safely, it might be a mitigation strategy.

As for my water tank on the roof, it might already be hotter than the fuel. I didn't buy it to heat the water, just carry it, but heat the water it does!
 

grinchy

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Is the area at top/back of engine in the engine bay a possible location?
 

bloc

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Is the area at top/back of engine in the engine bay a possible location?
Temps there would still be elevated and struggle to do much cooling..

For an air/liquid cooler we’d want as much ambient airflow as possible.
 
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Is the area at top/back of engine in the engine bay a possible location?

Some insight, I recently idled the truck while monitoring variables on a mild 80*F day. Intake air temp would start 5-10 degrees above ambient. After 15 minutes, was at 150*F. That's at the fender outside of the engine bay. Inside the engine would be that much hotter.
 
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I hear all the time. "My rig doesn't run hot". I ask how do you known? "Gauge on dash". Right!

Use any device hooked to OBD port, and read ECT, IAT & AT temps. If boiling/venting fuel, 99 out of 100 will see ECT, IAT & AT are running hot. Yet water temp gauge on dash isn't showing it is! AT temp light is not on.
 

bloc

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I hear all the time. "My rig doesn't run hot". I ask how do you known? "Gauge on dash". Right!

Use any device hooked to OBD port, and read ECT, IAT & AT temps. If boiling/venting fuel, 99 out of 100 will see ECT, IAT & AT are running hot. Yet water temp gauge on dash isn't showing it is! AT temp light is not on.
Toyota must be pretty bad at designing cooling systems for a vehicle with Genuine Toyota pump, radiator, thermostat, fan clutch, belt, idler and tensioner pulleys, coolant, and most hoses with less than 30k miles to run hot while running passes in 70-80 degree temps in low range at 1000lb under gross weight and only marginally taller tires than stock.

I’m fully aware the mid range of the stock coolant gauge is numb to the world, it’s much like other Toyotas on which I’ve done the resistor mod. But how much hotter will something run without any indication on the gauge? 20f higher than stock? And that alone is supposed to add more heat to the fuel system than it’s designed for? Keep in mind these trucks are designed to survive for a few hundred thousand miles in Africa. Often BEAT ON in the dunes in the Middle East.

I’m not saying this isn’t a contributing factor, but there are too many people here whom I trust to have dialed cooling systems that this has happened to.
 
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TheGrrrrr

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If anyone wants to analyze some data, I have posted up all of my OBD Fusion Logs from Red Cone, where I did intermittently smell gas in the cabin.

 

linuxgod

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I hear all the time. "My rig doesn't run hot". I ask how do you known? "Gauge on dash". Right!

Use any device hooked to OBD port, and read ECT, IAT & AT temps. If boiling/venting fuel, 99 out of 100 will see ECT, IAT & AT are running hot. Yet water temp gauge on dash isn't showing it is! AT temp light is not on.
My rig doesn’t run hot! :)

Ok not entirely true. Took this today while going over Rabbit Ears Pass near Steamboat Springs. 9300’, 14k lbs GCWR (truck + trailer). A/T and engine oil temps get hot, but coolant stays normal at 196F. No fuel boiling out of the tank.

I wish I’d used my dashboard on red cone as I did have a little “leakage” at the gas cap there. I didn’t have any on Mosquito Pass but I did fire up the dashboard and all my temps were 196F or less (coolant was 185F or thereabouts). That was going up te pass in 1st gear, 4Lo, so not exactly fast.

No gas cap leakage going over Imogene on Thursday and that’s 13k’, though I think I could smell some gas vapors. Then again I followed a group of ten 40/60/62/80 rigs over so lots of smells from them mixed into my cabin.

All anecdotal data but throwing it out there for future reference maybe it’s helpful to someone

99F68192-DBCA-4737-82D3-51F1D330DAD6.png


F7B81231-DFD9-4354-A975-208436ECAC7C.png
 
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Was playing in the mountains this past weekend and experienced some fuel vapors. It was distinctly coming from the EVAP vent and not the fuel fill. It would be hard to distinguish in a stock setup as the vent is at the cap, but in an LRA setup, the vent is behind the wheel well and it was definitely coming from that.

This was at a bit over 7300 ft. After a long 3 hrs of crawling and summiting at noon. 91 octane purchased at sea level. New EVAP canister replaced earlier this year.

Engine and tranny cool as a cucumber. But you can see with all the slow crawling (was in low range all morning), that there's plenty of undercarriage heat as indicated by the intake air temp @ 160F. I have a stock underbody.

1661183439934.png
 
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Was playing in the mountains this past weekend and experienced some fuel vapors. It was distinctly coming from the EVAP vent and not the fuel fill. It would be hard to distinguish in a stock setup as the vent is at the cap, but in an LRA setup, the vent is behind the wheel well and it was definitely coming from that.

This was at a bit over 7300 ft. After a long 3 hrs of crawling and summiting at noon. 91 octane purchased at sea level. New EVAP canister replaced earlier this year.

Engine and tranny cool as a cucumber. But you can see with all the slow crawling (was in low range all morning), that there's plenty of undercarriage heat as indicated by the intake air temp @ 160F. I have a stock underbody.

View attachment 3093963
How often do you have to replace the evap canister on the LRA?
 
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Glad I that I found this thread. Wanted to add my "rig" to the list of many others with the fuel vapor smell. Live in Colorado, and getting very frustrated taking the family out for an adventure and wind up getting lightheaded. It happens almost every time we take it "wheeling" but it's guaranteed to be pretty bad on the Kingston Peak trail if anyone is familiar with it.

It's a 2016 with 90k built up very heavy including the BB skids. I am interested in seeing how the fuel cooler goes. I am also wondering if adding a "snorkel" might help lower IAT a bit for my situation.

We are also doing a week long trip of CO including the Alpine Loop coming up this weekend. I'm considering buying a new Vapor Canister before the trip and hoping to get a few months or a year of not smelling fuel vapors. Has anyone tried aftermarket canisters?

I hope this thread continues!

-Matt
 

bloc

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Glad I that I found this thread. Wanted to add my "rig" to the list of many others with the fuel vapor smell. Live in Colorado, and getting very frustrated taking the family out for an adventure and wind up getting lightheaded. It happens almost every time we take it "wheeling" but it's guaranteed to be pretty bad on the Kingston Peak trail if anyone is familiar with it.

It's a 2016 with 90k built up very heavy including the BB skids. I am interested in seeing how the fuel cooler goes. I am also wondering if adding a "snorkel" might help lower IAT a bit for my situation.

We are also doing a week long trip of CO including the Alpine Loop coming up this weekend. I'm considering buying a new Vapor Canister before the trip and hoping to get a few months or a year of not smelling fuel vapors. Has anyone tried aftermarket canisters?

I hope this thread continues!

-Matt

Short term I think the only thing that would help is simply keeping the vapors outside the passenger compartment. Maybe try keeping the windows on that side closed, if you aren’t already.

I generally wheel with windows up to keep the dust out and rarely have the odors get inside.. mostly when I stop.

If you do replace the CC please post with your results whether it works or not.. I’m curious if this will help.
 

bloc

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Was playing in the mountains this past weekend and experienced some fuel vapors. It was distinctly coming from the EVAP vent and not the fuel fill. It would be hard to distinguish in a stock setup as the vent is at the cap, but in an LRA setup, the vent is behind the wheel well and it was definitely coming from that.

This was at a bit over 7300 ft. After a long 3 hrs of crawling and summiting at noon. 91 octane purchased at sea level. New EVAP canister replaced earlier this year.

Engine and tranny cool as a cucumber. But you can see with all the slow crawling (was in low range all morning), that there's plenty of undercarriage heat as indicated by the intake air temp @ 160F. I have a stock underbody.

View attachment 3093963
Something like this clamped to the fuel lines could help us determine supply (also tank) and return temperatures, and maybe correlate that with excess vapor production.. I’m trying to figure out how long the leads are to see if I should try doing it before my trip later this month.

F73597CF-F5C6-47A1-B3DF-5D13BDDD6553.jpeg
 
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We know fuel vapor issues aren't unique to the 200-series. It's possibly exacerbated by the design parameters, that has their bits tucked up higher than the frame rail and tight together. Most every other body on frame architecture I see usually has bits hanging lower, including the taco and 4Rs.

I think using the 100-series as a template for solving this issue is still key here.

I recently pulled my gas tank to replace a fuel pump. Took a closer look while there. One of the key areas IMO is extending the heat shield at the snot of the tank closest to the cat. To reduce radiant heat directly from the cat, but also reduce the convection of heat up and over the tank. The stock tank armor is double ply is key areas, but it can certainly go further up to reduce heat transfer in slow crawling situations.

1662485246803.png


Here's what it looks like without the tank armor in place.
1662485404539.png


There's a gap that can be bridged between the shiny heat shield that protects the body, and the armor of the gas tank. That's going to be my first area to attack.

How often do you have to replace the evap canister on the LRA?

I don't think it's a problem with the evap canister. Mine is new from only a handful of months ago, replace for a separate reason (corrosion from moisture coming in from the LRA breather). Even my brand new evap canister still had symptoms of vapor.
 
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My first encounter with this was this weekend in the Uinta mountains in northern Utah. I run a 2015 LC200 and was pulling 4200 pounds, climbing a consistent vertical from about 7000 feet to over 10,000 feet crawling on very rough terrain. Ambient temps were in low 70s at that time and dropped the higher we got. I did not see any visible signs of gas, but the smell was very apparent. Before we hit the trail, I fueled up twice, once at 4500 feet and another at around 6800 feet - both standard 10E/87. Once we were up and over the climb, the smell went away no matter the altitude. Anecdotally, I attribute it entirely to the tow weight and slow/rough crawl. I spend most of my time at high altitudes and have not experienced this ever before. But this was the first time I was pulling 4k+ and crawling in a steep vertical for an extended period of time over rough terrain. Once I set up camp and unhitched, we went wheeling again at 10k and had no issues.
 

bloc

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or something like this
Amazon product

I suspect the standard k-type thermocouples will be easier to get the actual measuring portion flush with the fuel line surface under for example a regular hose clamp, to get readings as accurate as possible. The tapered ends of typical meat thermometers can keep the internal thermocouple spaced off the object to be measured. Though great for getting meat dialed in..
 
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I have no doubt that fuel temperature is directly correlated to fuel vapors. I tend to want to just jump to solutions, but you've guys got me thinking that data would still be useful. If only to characterize the effectiveness of various solutions. Another science project?

I think something like a remote BBQ thermometer like Meater, aluminum taped to a metal fuel line, may offer sufficient insight? Would have to find a portion of line that is relatively unaffected by ambient heat.

Amazon product
 

grinchy

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I suspect the standard k-type thermocouples will be easier to get the actual measuring portion flush with the fuel line surface under for example a regular hose clamp, to get readings as accurate as possible. The tapered ends of typical meat thermometers can keep the internal thermocouple spaced off the object to be measured. Though great for getting meat dialed in..
Agreed, I suspect that simply removing the TC wire from the meat thermometer tube would resolve this issue. usually they slide right out.

it was the BT nature and built in temperature logger on the app that makes something like this easy to monitor that I think are bigger wins.
 

bloc

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Would have to find a portion of line that is relatively unaffected by ambient heat.

In my head at least, there is enough fluid moving through the line that ambient temps shouldn't impact the temperature of the fuel line and any thermocouple in good contact with it. To support this, I noticed a metal guard on the driver's side frame rail over the blank fuel line and believe that surrounds the fuel filter installed in other markets. A filter would have a lot of surface area for the flow rate, and therefore allow radiant and convective heat to impact fuel temps. Toyota makes no attempts to similarly shield regular fuel lines unless they get into really close proximity to very hot things.

But, with a temp reading solution we could monitor temps of the line as it exits the pump module, goes along the frame rail, then enters the engine bay. And back.

it was the BT nature and built in temperature logger on the app that makes something like this easy to monitor that I think are bigger wins.

Good points.
 

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