This past weekend I had the 200 at about 5000 ft in 95 degree weather and had the boiling fuel issue. Seems to be the norm, I guess....
Gas/Fuel vapors/fumes visible from gas door (1 Viewer)
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Interesting - I live at about 4500ft and it's been between 90 and 105 degrees all summer, only time I saw any vapors or dripping below the fuel door was low speed on trail. Last year I had it up around 7000-13000ft at much lower temperatures but also low speed on trail and didn't notice anything.
nwfl4runner
GOLD Star
Circling back to this regarding a potential in-line fuel cooler - my spare doesn't fit underneath anymore so there's room for activities. Where the return line connects to the tank it's a quick connect fitting. Theory would be go quick-connect to AN-8, run stainless braided to a Setrab cooler (FP119M22I) mounted above the rear frame rail near the charcoal canister, then return with an AN-8 to quick connect adapter so it plugs back into the stock connector. In theory it's plug and play, and doesn't require any butchering on the stock system. Thoughts?
My thoughts are i would love a guinea pig to pave the way!
More seriously, it is way out of my expertise but I definitely think many would welcome a somewhat easy solution. I get vapors even at low altitudes and mild temps. Just 4 low seems to do it. If it was plug and play as you suggest and easy to remove, I'd have no problem doing it.
Not a bad idea to fit an inline cooler, especially if it's plug and play.
Thinking outside of the box, indirect cooling or insulation in key areas may also be able to help. The problem is airflow and low speeds. Combined perhaps with skids or bumper mods that further trap heat.
Could be a layered solution.
- Applying insulation like this in key areas. Amazon product ASIN B000E243AW- Maybe fuel cooler?
- Maybe a small active fan in a key area of the skids?
There's a really great thread in the 100-series forum where someone added a temp prob to their fuel system and systemically worked to address several heat sources and greatly reduced the thermal load on the fuel system.
forum.ih8mud.com
Thinking outside of the box, indirect cooling or insulation in key areas may also be able to help. The problem is airflow and low speeds. Combined perhaps with skids or bumper mods that further trap heat.
Could be a layered solution.
- Applying insulation like this in key areas. Amazon product ASIN B000E243AW- Maybe fuel cooler?
- Maybe a small active fan in a key area of the skids?
There's a really great thread in the 100-series forum where someone added a temp prob to their fuel system and systemically worked to address several heat sources and greatly reduced the thermal load on the fuel system.
Gas tank building excessive pressure & fuel smell. Dangerous for sure! Why does this happen?
I've had this issue with and without full Dissent skids. In fact the single worst time I had fuel boiling out of my filler neck was without any after market skids. So I've ruled that out as a main cause, it could however be a factor in making a vehicle without a properly maintained cooling...
forum.ih8mud.com
So does this mean that Budbuilt or Victory skids may contribute more to this since they aren’t ”vented” vs Dissent or Slee which have cutouts around the cats?
Bud Built (Rob) installed lots of temp sensors before and after and found the main heat source to be the engine using fuel to cool the fuel system. I see vents on skid plates as adding horse power since you still have cross flow for air like OEM skids.
I have had many conversations with Rob talking about adding a fuel cooler with a fan in front of the radiator, but I just haven't put my mind and back into it yet.
I have had many conversations with Rob talking about adding a fuel cooler with a fan in front of the radiator, but I just haven't put my mind and back into it yet.
I recall in some of Victory's early tests, they experienced issues of fuel boiling and had to take the skids off on the trail.
I'd put them all in the same bucket as exacerbating this, some more than others, and all more than OEM. The game with fuel boiling is a matter of total heat into the fuel system, so a totality of contributors. Even if some designs contribute minimally more, it ultimately puts the total system closer to the boiling threshold. Then combined with extreme environmental conditions...
There was a great thread on the 100-series forum where an individual added a temp probe directly in the fuel system (only way to really understand more heat input). Then systemically working off significant contributors. Moving fuel lines off the engine block, onto the firewall. Adding heat shielding in key areas. An approach like this is what we need on the 200-series, possibly making things better than stock, or able to compensate for heavy skids underneath, and/or more extreme environmental conditions.
2001LC
SILVER Star
All belly pans obvously do trap in more heat, than a stock 100 or 200 series cross member they replace would. The #1 and #2 skid are less of a concerns, but sure they'd retain more heat and most vent less than stock. Also consider, the mass of all those and of the bumper & winch. Also how bumper & winch may block air flow, more than a stock bumper. Also how they'd retaining summer radiant heat.
But they're only a contributing factor to fuel venting from cap, not the cause IMHO. I'd point-out, there are many build 100 & 200 series with full armor of all years, that are not venting fuel vapor excessively (boil fuel).
I find most these excessively venting fuel vapor. Engine's are running hot or even overheating. Which those monitoring ECT, will typically see ECT routinely jumping over 200f, 210f or even higher coolant temps if they've a fuel venting issue.
#1 coolant system in need of service. i.e: rad fins clogged/blocked, thermostat and or rad cap sticking, low coolant, wrong coolant mixture, weak fan clutch, slipping fan belt (weak tensioner/junk belt). It's rare, I see one not in need of a coolant service on some level.
#2 engine running lean, raising cylinder head temp. Some of the cause of this are: Vacuum leak(s), EVAP system malfunction, Fuel pump flow an/or fuel pressure low, Fuel sock, filter and or injector clog (restricting flow), Increased resistance (weak pump motor, bad resistor, resistor heat sink blockage, wiring building high resistance, low voltage, poor ground, etc) in power to fuel pump motor.
But they're only a contributing factor to fuel venting from cap, not the cause IMHO. I'd point-out, there are many build 100 & 200 series with full armor of all years, that are not venting fuel vapor excessively (boil fuel).
I find most these excessively venting fuel vapor. Engine's are running hot or even overheating. Which those monitoring ECT, will typically see ECT routinely jumping over 200f, 210f or even higher coolant temps if they've a fuel venting issue.
#1 coolant system in need of service. i.e: rad fins clogged/blocked, thermostat and or rad cap sticking, low coolant, wrong coolant mixture, weak fan clutch, slipping fan belt (weak tensioner/junk belt). It's rare, I see one not in need of a coolant service on some level.
#2 engine running lean, raising cylinder head temp. Some of the cause of this are: Vacuum leak(s), EVAP system malfunction, Fuel pump flow an/or fuel pressure low, Fuel sock, filter and or injector clog (restricting flow), Increased resistance (weak pump motor, bad resistor, resistor heat sink blockage, wiring building high resistance, low voltage, poor ground, etc) in power to fuel pump motor.
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With the OP, being in the same general area, my guess the problem in some ways is exacerbated with us being at high altitude. As you increase in altitude the boiling temp deceases due to lower ambient air pressure. Also vapors are going to go from high pressure to low pressure environment.
I have a pretty solid espresso setup and sadistically take it with us when we ski over the weekend. Boiling temp drops from 201F at 5500’ asl to 189F around Breckinridge which is 10K’ asl. I have to drop my shot temperature and do some other voodoo from what roasters typically recommend because most are at or near sea level. Once the espresso leaves the group head, which is a sealed environment, it’s exposed to ambient conditions. So if you’re over ambient boiling temps pulling the shot, you can caramelize the sugars in the coffee.
Splitting time between CO and AZ, we’ve got the worst of both worlds. Lower boiling temps and high ambient temps. Anyone whose lived in AZ knows how the ground radiates crazy heat during the summer until 11-12 at night.
Budbuilt hasn’t shipped my skids yet but I may ask them to cut a few vent holes/Lou ears around the cats and maybe adding a couple like dissents gap plate in the front skid to facilitate more airflow.
@2001LC good point on belly pans. Maybe greater attention needs to be paid to heat management and airflow inside the “captive area”. Heats generally a bad thing… I liken this to entertainment cabinets that have poor ventilation and people wonder why their electronic keep dying. Poor thermal management.
I have a pretty solid espresso setup and sadistically take it with us when we ski over the weekend. Boiling temp drops from 201F at 5500’ asl to 189F around Breckinridge which is 10K’ asl. I have to drop my shot temperature and do some other voodoo from what roasters typically recommend because most are at or near sea level. Once the espresso leaves the group head, which is a sealed environment, it’s exposed to ambient conditions. So if you’re over ambient boiling temps pulling the shot, you can caramelize the sugars in the coffee.
Splitting time between CO and AZ, we’ve got the worst of both worlds. Lower boiling temps and high ambient temps. Anyone whose lived in AZ knows how the ground radiates crazy heat during the summer until 11-12 at night.
Budbuilt hasn’t shipped my skids yet but I may ask them to cut a few vent holes/Lou ears around the cats and maybe adding a couple like dissents gap plate in the front skid to facilitate more airflow.
@2001LC good point on belly pans. Maybe greater attention needs to be paid to heat management and airflow inside the “captive area”. Heats generally a bad thing… I liken this to entertainment cabinets that have poor ventilation and people wonder why their electronic keep dying. Poor thermal management.
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CharlieS
GOLD Star
I am in Wyomkng only at 5000 ft, gas from a Mobil in South Dakota, don't think I overfilled (but don't know for sure). I have an LRA 12.5, and full Budbuilt skids. We've driven 2000 miles in the last several days (over 3000 in the last three weeks), on and off road and didn't have any fill issues. The last few days have been 95-101 Fahrenheit, and I can only imagine how hot things are getting behind the skids. We stopped for gas near Devil's tower and gas cap was under a lot of pressure. I slowly opened it to vent the pressure, and when I finally popped the cork, I think a tiny amount of fuel came out. I could see the vapors venting out the cap, and couldn't put any gas in the factory tank, The pump just kept shutting off every time I tried.
I transferred from my aux tank to get me to a campground, hoping that things might be better after the system cools overnight.
I've driven a ton of dusty stuff in the last couple of weeks, so I'll check my prefilter and K&N vent filter on the LRA this morning. I did replace my engine air and cabin filters before this trip and they were in bad shape, I forgot to check the LRA vent. Hopefully it is as easy as this...
Then we'll be off to try to fill the tank again. Fingers crossed that we can fill the tank - we have a lot more ground to cover in the next two weeks (including LCDC).
I transferred from my aux tank to get me to a campground, hoping that things might be better after the system cools overnight.
I've driven a ton of dusty stuff in the last couple of weeks, so I'll check my prefilter and K&N vent filter on the LRA this morning. I did replace my engine air and cabin filters before this trip and they were in bad shape, I forgot to check the LRA vent. Hopefully it is as easy as this...
Then we'll be off to try to fill the tank again. Fingers crossed that we can fill the tank - we have a lot more ground to cover in the next two weeks (including LCDC).
bloc
SILVER Star
If you wait long enough, you will be able to fill it.
The process of boiling takes thermal energy out of the fuel, that’s kind of the point. In your case it means it may take a half hour or something but eventually it will calm down and you could add more to the tank. Not to mention any fresh fuel added, even slowly, cools the whole thing down to reduce vapor production.
Also getting to the fill station when the fuel hasn’t heated up yet or has had a chance to sit and cool would help.. like grabbing breakfast at a nearby restaurant or something then going to fill..
This surely sounds annoying but I think you’ll get it figured out easily.
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2001LC
SILVER Star
If engine air filter is getting clogged, it creates a rich fuel condition. ECM works to correct to a 14: 1 mix. A rich condition will drop cylinder head temp. So I doubt air filtration part of your issue.
I can not speak for the LRA, or if properly venting. But if engine running hot, you will have fuel boiling issues.
You've made no mention of ECT (engine coolant temp), if new radiator or if old radiator fins ever clean or thermostat & rad cap replaced. A proper function coolant is so import and so over looked!
Only radiator that I don't find fines need cleaning are new ones. The Toyota OM states: "clean radiator fins" as a regular PM.
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
Look up from underneath sides of radiator with flash lite. Is there muck in the fins? Yes, than clean it. This is where I'd start, then move on to engine tune up, stopping all vacuum leaks. Good & clean MAF, is also important. Additionally we're finding that blocking air flow around fuel pump resistor (On RH fender) with air pump or extra battery, is reducing FP resistors heat sinks ability to shed heat. Heat in electrical wires & components creates resistance, which reduces AMP to electric motors. If fuel pump spins too slow from reduced AMP's. It can create a low fuel flow/pressure to fuel rial. We than run lean, ECM works to correct. But cylinder head temp will go up, if still runs lean.
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CharlieS
GOLD Star
Thanks, that is really helpful info. I appreciate it.
bloc
SILVER Star
That's definitely progress.
I get a ton of dirt and dust on my LRA breather as well. It's become a maintenance item and I can definitely tell when it gets gunked up enough to affect fill speed in normal conditions. I'd imagine filling under fuel boiling conditions to be that much worse, to impossible, as the vent is key to letting fumes out when filling.
It was touched on in another thread, but using low range off-road is going to help overall cooling. Keeps the engine driven fan pushing more air, coolant circulating faster, transmission and torque converter temps lower.
Have fun out there!
It may help engine temperature, but the lower vehicle speeds will also lead to less air flowing around the gas tank, which might lead the fuel to not cool fast enough as the hot return fuel keeps getting dumped in.
There definitely seems to be a lot of inputs into the equation that affect how the problem presents itself.
Yup and yup. Many contributors here. I wasn't suggesting to use low range if driving conditions allow higher speeds than low range will do. At the same time, low range is useful for more than just crawling.
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