Gas puked out of filler cap and major vapor pressure

[gatormark91]

How much is the intake vsv? I probably should just get that too.

Is there a way to get techstream for under a mortgage payment that isn't Chinese virus laden?

Buy any MVCI cable off Amazon or eBay. Throw the included CD/DVD in the trash (it will probably be broken, anyway). Set up a virtual machine on your laptop using this link:

FAQ - How-To: TechStream In 5 Minutes

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[socalmtbiker]

I reported the issue when it occurred to and encouraged others to do so. The more reports the more likely auto makers will be forced to fix the issue-

Home | NHTSA

Get resources and info about staying safe on America’s roads. And, find out if there’s a recall on your car or how to report a vehicle safety problem.

www-odi.nhtsa.dot.gov

 

[8lifgr8]

I reported the issue when it occurred to and encouraged others to do so. The more reports the more likely auto makers will be forced to fix the issue-

Home | NHTSA

Get resources and info about staying safe on America’s roads. And, find out if there’s a recall on your car or how to report a vehicle safety problem.

www-odi.nhtsa.dot.gov

I will do that when I reach civilization. Thanks.

 

[suprarx7nut]

I never "top off" but I did do a test run up skyline. I did fill up full, but my symptoms did not show up until 3/4 tank. Then it vented while driving, the passing side by sides all gagged from the vapor plume as they passed me (10k feet). At lunch we dropped to 9500 ft and had the "boiling" sound, but there was no venting or smell. An hour into lunch it equalized and no pressure in the tank (I could open my cap).

I ordered a cannisters and cap for pickup at delta Colorado Toyota ($500). I hope it fixes it ..my symptoms aren't as bad as some on this thread, but it's crazy rediculous for 137k miles.

@suprarx7nut, it's getting progressively worse. Doing nothing is not an option, passing vehicles are literally driving through a cloud of gas, and there is enough that I'm probably wafting gallons into the atmosphere.

Attached is the photo of mine at 10k feet, the dust shows the path of the gas. I'd hate to imagine what it would look like at 13k..View attachment 2037284

My apologies, I didn't mean to infer that my permanent solution is to do nothing. I will start replacing and testing parts. I just meant that at that specific event, I did not open the cap, I did not immediately shut down the car, I did not do anything, etc...

 

[suprarx7nut]

I reported the issue when it occurred to and encouraged others to do so. The more reports the more likely auto makers will be forced to fix the issue-

Home | NHTSA

Get resources and info about staying safe on America’s roads. And, find out if there’s a recall on your car or how to report a vehicle safety problem.

www-odi.nhtsa.dot.gov

Complaint filed. Thanks.

 

[H E A V Y M E T A L]

Change the fuel pump. This fixed my issue.

 

[JPS]

This happened in Iraq all the time. Overland and even when the tank is damn near empty. We had no solution besides cool it down.

 

[8lifgr8]

Here is an update (TLDR: It helped, but didn't solve the issue):

I got my canister from Hellman Toyota out of Delta Colorado on my way from San Rafeal Swell to my camp at Ridgeway. I've been filling up with either premium ethanol or ethanol free when available. The part was inexcusably expensive at $440, but that's life. It does come with what appears to be a few filters and an electric valve. It also comes with one of the hoses. I asked for the intake "VSV", and we saw on the drawings what appeared to be it, but obviously it wasn't in stock. What I believe is the VSV is listed under "Evap Cannister Outlet" and contains what looks like the valve or filter and two hoses for $30. I'll probably order one as that part is ridiculously cheap.

Luckily for me, Toyota was kind enough to include one of the hoses with the cannister. When I got to my repair (which was easy, channel locks and 4 12mm bolts), this particular hose is the only one that showed signs of cracking. Probably why Toyota included it. Nice touch.

Job was done within a half-hour at the Ridgeway State Park Overflow Parking. The old cannister wasn't filled with gas and I was discouraged maybe I blew my $$.

Anyway, the next test was Mesa Verde, we would drive the San Juan mountain passes up and down in the morning and then the pavement of the National Park to our tours. It never got *that* hot, mid 80s, and Mesa Verde is roughly on the short side of 8k feet. When we parked and I put my ear to the cap, I could hear "breathing" but no "boiling". That was an improvement, but most importantly, no venting. No fuel smell. I was topping off whenever I could, because I wanted to test with a full tank.

The next day was Ophir Pass, 11,700 feet. We came up from the Ophir side, this side is more tore up, so I was in 4-low from the get-go. Sadly, for the test, it was only low 80s at best in the towns and cooler on the passes, so I didn't have as much ambient heating as when I was in the Swell. I *did* have a full tank of premium ethanol at the Shell station in Telluride going against me though (shout out to the Hundreds in the Hills participants that I chatted with at the station). So my tank was topped off, maybe less than a gallon used by the time I shifted into 4-low.

After getting out for a photo opp, I looked at my fuel door...there was signs that some fuel spilled out. I did climb from 8k to 12k quite quickly, so I guess that's expected (by Toyota standards anyway, I've never seen another 4wd do this). Was there a clear chimney of fuel vapor shooting off into the sky? No. I opened the door and stuck my nose at the gas cap and couldn't smell anything. Like Mesa Verde, you could hear the tank "breathing" but not boiling. I vented the tank, obviously some pressure but nothing terrible.

So in the end, it is MUCH safer than before the repair, but not totally fixed. I'll try the VSV valve and look into heat shielding, it would have been nice to test the climb at 90F or even 80F, but I'm just happy I wasn't trailing a gagging cloud of vapor for the passing side-by-side operators to choke on!

 

[J1000]

The problem will keep coming back because it's got nothing to do with ethanol or your charcoal canister, those are just bandaids on a big problem. The real problem is that the fuel lines run too close to the catalytic converter, causing the fuel to boil. I can't believe this isn't common knowledge on this forum yet.

Build a heatshield or it will happen again.

100 Caught fire & gas tank venting concerns

forum.ih8mud.com

Built the shield.

View attachment 1963223

View attachment 1963225

 

[8lifgr8]

Agreed, I will be looking into the heat shield as well.

 

[slacker24-7]

The heat shield fixed it for me as well as 2 friends 100,s a few years ago.
I’m also surprised this isn’t common knowledge by now

 

[gatormark91]

The problem will keep coming back because it's got nothing to do with ethanol or your charcoal canister, those are just bandaids on a big problem. The real problem is that the fuel lines run too close to the catalytic converter, causing the fuel to boil. I can't believe this isn't common knowledge on this forum yet.

Build a heatshield or it will happen again.

100 Caught fire & gas tank venting concerns

forum.ih8mud.com

The heat shield is also a bandaid, even if it works. If that helped, your cat might be partially blocked or something is possibly making your fuel trims too rich, causing the cat on that side to get too hot.

 

[gatormark91]

If you can hear ANY exhaust noise under the truck that isn't coming from the tailpipe, fix it now. If you are running an original muffler, drop it and check the top of it for pinholes. You can throw all the parts you want at your truck, but if you have an exhaust leak, you'll never get the fuel issue fixed.

 

[8lifgr8]

@gatormark91 , I did do your "metal shifter temp test", even after extensive climbs in 4-lo it wasn't warm at all.

 

[Tower1]

Same problem headed to Colorado pulling a 2500 lb trailer , the ethanol issue sounds documented and accurate but over the first pass past Denver rear passenger noticed the floor getting pretty warm ,my muffler is shot and leaking and in the process heating the fuel tank thus creating pressure, maybe ethanol is more prone to vaporizing with the added heat , a Borla cat back was ordered today

 

[gatormark91]

Same problem headed to Colorado pulling a 2500 lb trailer , the ethanol issue sounds documented and accurate but over the first pass past Denver rear passenger noticed the floor getting pretty warm ,my muffler is shot and leaking and in the process heating the fuel tank thus creating pressure, maybe ethanol is more prone to vaporizing with the added heat , a Borla cat back was ordered today

Yes, ethanol boils at a lower temperature than gasoline. When you tow a trailer, the gases from the exhaust leak gets stuck under the truck by the big slug of air that the trailer aerodynamics pushes in front of it.

 

[dinnertime]

Ethanol boils at 173 F at atmospheric pressure, but your fuel tank will be pressurized from gasoline evaporation/vaporization which starts at 93F. I'm not sure what the max pressure is before you evap system starts purging, I would have to do some sleuthing.

Obviously boiling points decrease with altitude at 10k feet the point point of ethanol is roughly 18.5 degrees lower @ 154.4 F. But the tank is under pressure, so id bet it hovers right around the 173F mark for the ethanol. Gasoline has a lot of variables into the boiling point, mainly the additive package so its difficult to get and accurate temp. It can be as low as 160ish degrees though..

Some people only experience fuel leaking/spray when they vent the cap, which makes sense. You're rapidly decreasing the pressure when the fuel may be below the boiling point at whatever altitude you're at, but above the boiling temp under pressure.

I think heat may be a big part of the issue, and making a better heat shield to keep the radiant heat off the fuel lines can't hurt. Id also put a heat sleeve on the lines by the exhaust and probably some sort of radiant heat barrier on the tank since the exhaust goes so close. I think the heat may be unavoidable when going slower on trails ect and you're not getting the best airflow under the chassis.

 

[nissanh]

Is there a gasoline return hose next to a coolant hose? I experienced the same issue in my corolla when I drove across the desert between Hoover dam and King man in AZ. I solve the issue by bypassing the coolant line.

 

[Hugh Heifer]

My experience last weekend FWIW.

2000 LC w/ 200,000 on the clock. I have recently smelled gas vapors near the left rear when parked regardless of full or not but not all the time.

Friday I was running 91 octane, about 94F. Had about 3/4 of a tank when I left home and drove through Asheville, NC so just a few thousand feet in elevation. Then on toward Georgia so not much over sea level. All highway.

I stopped to fill up and was pretty low (I ended up putting in 20 gallons). When I stopped to fill up a smelled an enormous amount of gas fumes and could see vapors. I cracked the cap and it just started blowing off fumes. As it began to slow I opened the cap and could see the fumes basically liquefying at the filler neck. This went on for about 10 more minutes.

I filled up, careful not to overfill again with 91.

Went another 45 miles to my destination and the truck reeked of gas outside around the back upon arrival and for several hours after. After a while I cracked the cap and it vented heavy. I burped it several time over the next hour.

I drove home two days later with no issues. Put over 20 gallons in when I get near home and there was no pressure in the tank. Had no codes and have not had any codes except ignition coils in years.

I had the truck in the Philippines and crawled through traffic on 100 degree days and never had this happen but the gas monkeys liked to overfill tanks there.