Gas tank venting upon opening cap. (1 Viewer)

[mep1811]

I've experienced a brand new issue Where I've been unable to just put in the gas nozzle in my tank and set the release lever and walk away.
I've been having to dribble gas into the gas tank.
Just recently after driving for several hours I stopped for gas open the gas cap and there was a venting of gasoline vapour and some gasoline droplets. The tank was a quarter full.
After about 5 minutes of the tank venting I was able to fill the tank normally.
I do smell like gas smell from the back of the truck .
I'm suspecting maybe the tank isn't venting properly.

The outside temperatures have been a 100 plus degrees but I never had this problem last year.
I'm going to open the tank in the morning when it's cool and see what happens.

Any suggestions? Thanks

 

[TeCKis300]

I think you have an LRA tank?

If so, I believe this is your issue and solution

Charcoal Canister / LRA Breather Fix

TL;DR 1) LRA charcoal breather plumbing and adapters are too small in diameter, limiting venting when filling the main tank tripping the gas pump. Needs 5/8" ID plumbing though to breather. 2) Breather filter is a maintenance item. Too much dust and dirt will plug the external breather filter...

forum.ih8mud.com

 

[Markuson]

I've experienced a brand new issue Where I've been unable to just put in the gas nozzle in my tank and set the release lever and walk away.
I've been having to dribble gas into the gas tank.
Just recently after driving for several hours I stopped for gas open the gas cap and there was a venting of gasoline vapour and some gasoline droplets. The tank was a quarter full.
After about 5 minutes of the tank venting I was able to fill the tank normally.
I do smell like gas smell from the back of the truck .
I'm suspecting maybe the tank isn't venting properly.

The outside temperatures have been a 100 plus degrees but I never had this problem last year.
I'm going to open the tank in the morning when it's cool and see what happens.

Any suggestions? Thanks

Boiling gas.
Happens in high temps.
Where are you located?
Utah?

 

[mep1811]

Boiling gas.
Happens in high temps.
Where are you located?
Utah?

Colorado now heading towards Utah. I opened the cap this morning no venting and the tank is filling normally. But then again the temperature is only about 80.

 

[mep1811]

I think you have an LRA tank?

If so, I believe this is your issue and solution

Charcoal Canister / LRA Breather Fix

TL;DR 1) LRA charcoal breather plumbing and adapters are too small in diameter, limiting venting when filling the main tank tripping the gas pump. Needs 5/8" ID plumbing though to breather. 2) Breather filter is a maintenance item. Too much dust and dirt will plug the external breather filter...

forum.ih8mud.com

Thanks Never had the issue last year with the same kind of temperatures.

When I get some place where I can I'll check that out.
Right now in Colorado at about 80ﾟ Opened the tank with no venting and filled normally.

 

[ElJayBird]

I used to have this issue in my 80 when at altitude, usually over 7000 ft or so. It was really bad when traveling through Co. Haven't had any problems with the 200 but haven't been much over 5-6000 ft in a while.

 

[bloc]

This can vary based on the individual tank of fuel you have as well. Plus as others said temp and altitude will contribute. I got curious about a gas smell around my 200 and opened the tank at Oh! Point near engineer pass and had a ton of boiling..

The good thing is our evap systems are so closely monitored if there were a real problem you’d likely be getting a light. Sucks that you have to fill so slowly though..

 

[mep1811]

I drove several hours at 106 degrees and no issues when I fueled up in Bluff,UT.

 

[cboyd]

i had similar issues with my 100 and it ended up being the filler pipe going into the tank... the flexible corrugated pipe had separated the liner and was significantly blocking the line. It took me 20 mins or more to fill up. swapped the filler tube at the tank from the hardline and no issues since. the thread is here on mud

 

[linuxgod]

If you have boiling fuel, and/or if you know you're going to be up in elevation, I recommend filling with a tank of Premium (91+ octane). Anecdotally I've found I hardly ever need to vent my rotopax when I put premium in it, but if I put in 87 octane it swells like mad (at one point bubbling and spraying out when I vented too quickly).

 

[kreiten]

If you have boiling fuel, and/or if you know you're going to be up in elevation, I recommend filling with a tank of Premium (91+ octane). Anecdotally I've found I hardly ever need to vent my rotopax when I put premium in it, but if I put in 87 octane it swells like mad (at one point bubbling and spraying out when I vented too quickly).

I'd be interested to see if the higher octane works for others, but unfortunately didn't work for me. We tried different gas stations in Moab, different octanes, different levels in the gas tank when starting the trails etc.. We even tried leaving the gas cap partial open, off etc... I have had this happen on my rig over a dozen times, sometimes worse than others... At this point about once a week when my rig does a system check and throws the code I just reset it with my reset tool sitting in the door pocket. I've gotten so good at it somedays I just set my coffee down and grab the tool as I know it's proly the day to reset it Is it worth replacing the charcoal canister knowing I'll be back in Moab again soon, they are not cheap

 

[linuxgod]

Is it worth replacing the charcoal canister knowing I'll be back in Moab again soon, they are not cheap

Only if your state has mandatory emissions testing like mine does.

 

[kreiten]

Only if your state has mandatory emissions testing like mine does.

well there is that Damn this is def a flaw in the system... I have beat on my 100 series on trails with heat and elevation and never had it happen, sounds like others have... I have friends with 4Runners and Tacoma's that have never dealt with this either... I'm sure like people have said all brands deal with this to some extent but the problem appears worse in the 200?!?!

 

[linuxgod]

well there is that Damn this is def a flaw in the system... I have beat on my 100 series on trails with heat and elevation and never had it happen, sounds like others have... I have friends with 4Runners and Tacoma's that have never dealt with this either... I'm sure like people have said all brands deal with this to some extent but the problem appears worse in the 200?!?!

I wish I understood the evap system better, and had bigger cajonies to mess with anything involving fuel.

As an engineer, it's hard to debug the issue if it's not consistent and repeatable. My sense is that boiling fuel indicates a problem with pressure relief. Maybe it's as simple as a dusty or undersized breather element?

My hunch as well is that evap codes are a latent symptom, and it may well be that once you've gotten an evap code even if you solved the underlying problem the codes would keep returning because the charcoal canister is contaminated. That could point to why you'd keep seeing issues with a partial tank, for instance, once you've had a code already. Or I could be totally off base.

BTW the charcoal canister is part of the emissions system and the LC/LX come with IIRC an 8 year/80k warranty on those parts. So if anyone has a newer LC/LX which is still under warranty, I wouldn't hesitate to take it to the dealer and ask "WTF?" In fact if there's actually gas coming out of the gas cap and it's under warranty and the dealer won't help I'd call corporate and tell them how your vehicle is leaking fuel and is a fire hazard and how the local dealer isn't helping. Having worked in a big company before, I would not be surprised if nobody in Toyota engineering has heard about this problem - most likely all the engineers see are overall component failure/replacement rates over time and a few charcoal canisters on a low production LC are likely statistical noise to them.

 

[Bighead]

If you have boiling fuel, and/or if you know you're going to be up in elevation, I recommend filling with a tank of Premium (91+ octane). Anecdotally I've found I hardly ever need to vent my rotopax when I put premium in it, but if I put in 87 octane it swells like mad (at one point bubbling and spraying out when I vented too quickly).

I run 91+ in my 200 and haven’t noticed any venting issues. I live at 9000’+ and have been driving on the latest hot CO days with major elevation changes. So far so good.

With that said I received the same advice when experiencing the venting on my 100-series and it didn’t make a difference. It only stopped when I swapped the charcoal canister.

 

[bloc]

As well as temp, I’m betting a big factor is the chemistry of the individual tank of fuel.

In the past I think someone posted a link or chart to data on fuel volatility compared to octane..

 

[bloc]

Is this something that can be reported to NTSB or similar? Or is that only for actual incidents of injury/death?

I thought this was only happening on trail, but if it’s driving down the road that is another ball of wax.

@TeCKis300 @linuxgod or anyone else towing heavy.. have you noticed more of an issue with fuel boiling in-tank when hauling a big trailer?

 

[linuxgod]

Is this something that can be reported to NTSB or similar? Or is that only for actual incidents of injury/death?

I thought this was only happening on trail, but if it’s driving down the road that is another ball of wax.

@TeCKis300 @linuxgod or anyone else towing heavy.. have you noticed more of an issue with fuel boiling in-tank when hauling a big trailer?

I've never had my tank boil, to my knowledge. I did have one time when I was climbing to the top of Grand Mesa, CO with the trailer in tow (in 2nd gear at about 30 mph) that I stopped near the top to take a photo and noticed the smell of gas. It wasn't leaking out the tank though. But otherwise despite running about 8300# GVWR and a 6000# trailer I've not had any problems myself. (Probably just jinxed myself tho)

I'll be in Moab after the LCDC so I'll let you know how it goes, but the last time I was there in 2017 I didn't have any issues

 

[bloc]

I've never had my tank boil, to my knowledge. I did have one time when I was climbing to the top of Grand Mesa, CO with the trailer in tow (in 2nd gear at about 30 mph) that I stopped near the top to take a photo and noticed the smell of gas. It wasn't leaking out the tank though. But otherwise despite running about 8300# GVWR and a 6000# trailer I've not had any problems myself. (Probably just jinxed myself tho)

I'll be in Moab after the LCDC so I'll let you know how it goes, but the last time I was there in 2017 I didn't have any issues

What time of year for that 2017 Moab trip?

 

[mep1811]

No issue with boiling gas or venting. I still have to dribble gas into the the main tank. The aux tank I can set the nozzle and it will fill without issue.