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

[nikoli]

What year? In my '99 with the charcoal canister under the hood, I will smell fuel vapors in the cabin if the fuel boils (well over 100°F and hard driving) from the over pressure vent line that comes out of the front of the canister and runs down into the fender. I had that the other day and when I parked and popped the hood I could hear/feel that line gurgling.

05 Lx470

 

[Cruiser Brains]

If you haven’t already, may inspect exhaust and muffler to see if there are any leaks or holes that could be heating your gas tank. Mine had holes in the top of the muffler that could only be seen when I removed the tank.

Smelling strong vapor in the cabin today. Just normal driving. Not even hot out.

 

[nikoli]

Thanks but that ain’t it. These things are just designed for s***. Toyota blew it imo.

 

[Rhetoric]

Thanks but that ain’t it. These things are just designed for s***. Toyota blew it imo.

Yeah they really messed up on these 17 - 26 year old garbage vehicles designed in Windows 95 machines.

 

[nikoli]

I appreciate that… but I also have a ‘92 Pickup 3.slow with 264k on the clock that never smells like gas.

If you check this thread you will find I have an ‘03 LC and an ‘05 LX with this problem. Somebody definitely blew it at Toyota, and frankly it’s amazing they haven’t had to address it.

Yeah they really messed up on these 17 - 26 year old garbage vehicles designed in Windows 95 machines.

 

[Eyedaho]

I appreciate that… but I also have a ‘92 Pickup 3.slow with 264k on the clock that never smells like gas.

If you check this thread you will find I have an ‘03 LC and an ‘05 LX with this problem. Somebody definitely blew it at Toyota, and frankly it’s amazing they haven’t had to address it.

I have driven along wondering if what I'm smelling is above or below the LEL of 87 octane ethanol juiced gasoline.

 

[ScotyDosentKnow]

I appreciate that… but I also have a ‘92 Pickup 3.slow with 264k on the clock that never smells like gas.

If you check this thread you will find I have an ‘03 LC and an ‘05 LX with this problem. Somebody definitely blew it at Toyota, and frankly it’s amazing they haven’t had to address it.

Weird you would use an engine known for eating head gaskets as an example of how its done lol

 

[nikoli]

Weird you would use an engine known for eating head gaskets as an example of how its done lol

It’s also weird that the only head gasket I’ve ever had to replace was on my meticulously maintained ‘05 LX.

Frankly my Pickup has been far and away the most reliable and trouble-free vehicle I’ve ever owned… and it’s not particularly close.

 

[SoularVibe]

Yeah they really messed up on these 17 - 26 year old garbage vehicles designed in Windows 95 machines.

 

[SoularVibe]

i as well have been battling the fuel pressure and boiling issues... since i've owned the cruiser 10 years ago. I've tried a few things, but recently what seems to have solved the issue is replacing the CC, replaced the Charcol , BUT I also drilled out the BB valve in the top lid. It was restricting the vacuum side. after removing that BB, i installed a vacuum gauge with a 1 way valve to keep vacuum going one direction on the small vacuum line (there's a "Y" right before the blue vacuum control with 4-5 lines to it.) Before the drilling, i was seeing pretty high vacuum 12-15, after, i was seeing about 4-5; which indicates it has more flow now, allowing the system to "vacuum out" fumes from the CC faster.

the vent line out the bottom of the CC is routed under the driver door area with a 1way valve and a filter on the end.

Also have a passive 24" fuel cooler, which didn't have any noticeable effect on the problem. I have a fuel temp / ethanol gauge, and monitored fuel temps and ethanol content when the issues occured. It was MUCH better with Ethanol free fuel, but still happened.

I have not had a pressurized tank or smell since! Super stoked! A/C, mountains, 100+ degrees, doesn't care anymore.

happy to share pics if anyone cares to see my "alternative" solution

don't judge, it works.

 

[2001LC]

i as well have been battling the fuel pressure and boiling issues... since i've owned the cruiser 10 years ago. I've tried a few things, but recently what seems to have solved the issue is replacing the CC, replaced the Charcol , BUT I also drilled out the BB valve in the top lid. It was restricting the vacuum side. after removing that BB, i installed a vacuum gauge with a 1 way valve to keep vacuum going one direction on the small vacuum line (there's a "Y" right before the blue vacuum control with 4-5 lines to it.) Before the drilling, i was seeing pretty high vacuum 12-15, after, i was seeing about 4-5; which indicates it has more flow now, allowing the system to "vacuum out" fumes from the CC faster.

the vent line out the bottom of the CC is routed under the driver door area with a 1way valve and a filter on the end.

Also have a passive 24" fuel cooler, which didn't have any noticeable effect on the problem. I have a fuel temp / ethanol gauge, and monitored fuel temps and ethanol content when the issues occured. It was MUCH better with Ethanol free fuel, but still happened.

I have not had a pressurized tank or smell since! Super stoked! A/C, mountains, 100+ degrees, doesn't care anymore.

happy to share pics if anyone cares to see my "alternative" solution

don't judge, it works.

Very cool
I'm very interested.
Do you have a thread on the whole procedure? If not, one would be great!

What year & mileage?

A really great test: Document all data (ECT, FT, MAF, CAT temps, pressures, vacuums, etc..) you can on a hot day over some rocky passes. Then swap in a new OEM CC, with all system stock. See if boiling comes back.

 

[SoularVibe]

Very cool
I'm very interested.
Do you have a thread on the whole procedure? If not, one would be great!

What year & mileage?

A really great test: Document all data (ECT, FT, MAF, CAT temps, pressures, vacuums, etc..) you can on a hot day over some rocky passes. Then swap in a new OEM CC, with all system stock. See if boiling comes back.

94 with 245k

pressurized BAD when hot and at altitude. tried the GM CC, same deal. Dealt with it for years. tried ethanol free fuel... prob was a little better. Added fuel cooler, not really any difference. Got another OEM CC, put in new charcoal. I noticed that when i sucked on the port that runs to the VSVs, it seemed very restricted. So I drilled out the BB valve and it then had a nice free flow ... sealed it all back up and no pressure since.

 

[ScotyDosentKnow]

It’s also weird that the only head gasket I’ve ever had to replace was on my meticulously maintained ‘05 LX.

Frankly my Pickup has been far and away the most reliable and trouble-free vehicle I’ve ever owned… and it’s not particularly close.

And Ive done head gaskets on no fewer than 25 3.0's. I used to make a decent amount of extra cash picking up dead pickups, replacing the head gaskets, detailing and reselling them lol

 

[SoularVibe]

94 with 245k

pressurized BAD when hot and at altitude. tried the GM CC, same deal. Dealt with it for years. tried ethanol free fuel... prob was a little better. Added fuel cooler, not really any difference. Got another OEM CC, put in new charcoal. I noticed that when i sucked on the port that runs to the VSVs, it seemed very restricted. So I drilled out the BB valve and it then had a nice free flow ... sealed it all back up and no pressure since. View attachment 3688524

View attachment 3688522

sorry mine's an 80 ... just realized this is the 100 series thread

 

[nikoli]

And Ive done head gaskets on no fewer than 25 3.0's. I used to make a decent amount of extra cash picking up dead pickups, replacing the head gaskets, detailing and reselling them lol

Really don’t know what you’re lol’ing about, or why you’re even talking. Kinda pathetic tbh.

 

[4gotalot]

sorry mine's an 80 ... just realized this is the 100 series thread

Nah, you're good. Thanks for the info here and would like to hear more. I have a 2011 LC200 with the same fuel temp problems so this is good info.

 

[nikoli]

Nah, you're good. Thanks for the info here and would like to hear more. I have a 2011 LC200 with the same fuel temp problems so this is good info.

So we have on this page alone, confirmed three consecutive generations of cruisers with this issue.

Interesting.

 

[2001LC]

sorry mine's an 80 ... just realized this is the 100 series thread

Still interesting.

I've held for a long time, CC is a leading cause of fuel boiling. That a clogged CC, results in increased fuel tank pressure.
That all systems must be in order (i.e.: ECT, engine & transmission) first, or we risk flooding/clogging CC again.

IMHO. The fact you solved with CC and mods to relieve pressure, is important info. That all other attempts like fuel cooler, fuel type/blend had little to no help.

Pressure = heat. Heat = pressure. You've demonstrated reducing pressure is the key.

 

[nikoli]

Still interesting.

I've held for a long time, CC is a leading cause of fuel boiling. That a clogged CC, results in increased fuel tank pressure.
That all systems must be in order (i.e.: ECT, engine & transmission) first, or we risk flooding/clogging CC again.

IMHO. The fact you solved with CC and mods to relive pressure, is important info. That all other attempts like fuel cooler, fuel type/blend had little to no help.

Pressure = heat. Heat = pressure. You've demonstrated reducing pressure is the key.

So now all we need is for Toyota to recall our CCs and replace with a properly designed CC.

 

[Eyedaho]

Still interesting.

I've held for a long time, CC is a leading cause of fuel boiling. That a clogged CC, results in increased fuel tank pressure.
That all systems must be in order (i.e.: ECT, engine & transmission) first, or we risk flooding/clogging CC again.

IMHO. The fact you solved with CC and mods to relive pressure, is important info. That all other attempts like fuel cooler, fuel type/blend had little to no help.

Pressure = heat. Heat = pressure. You've demonstrated reducing pressure is the key.

Pressure can cause vapors to escape, but will increase the fuel boiling point. That's why water boils at a lower temperature at a higher elevation. It's also why radiator caps are designed to maintain pressure in the cooling system.