its a vicious circle it is.
Gas tank building excessive pressure & fuel smell. Dangerous for sure! Why does this happen?
- Thread starter 2001LC
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Eyedaho
SILVER Star
Fo shizzle.
- Thread starter
- #1,004
First thing I'd do is check the gas cap. Make sure seal in good condition and tight. If older or not OEM gas cap, I'd replace. Clear codes and see what comes back.
I wanted to highlight the wisdom of this piece of the puzzle. It appears other Toyota engine evap systems report similar issues as we 100's do.
Here's a great writeup of the DIY fix LS 430 owners have used to service the VSV mounted to the intake; with shop manual references.
Note: I attempted this and it was a 1/2
job. Unfortunately, it was not the only culprit in my hot fuel saga and I ended up replacing my charcoal canister. Ordinarily a job of few , but hindered by the LRA AUX tank that had to be dropped 
to access the canister.I haven't given it a proper long drive to observe any MPG changes etc., but I immediately noticed it idles better. Interestingly, fuel poured out of the old canister when removed - that couldn't have been correct. I expect to smell less strong fuel odor now, and hopefully improve the efficiency of the EVAP system.
Last summer I had fuel boiling in the high Colorado mountain passes (2000 LC). I insulated my fuel tank (the sides facing the exhaust) and the fuel lines running along the frame rail. No issues this year, with similar weather.
Notes from the tech at my favorite local Toyo shop…
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Finding:
found multiple dtc's for the evap system. all listed below. visually inspected the system and found no leaks. i tested all vsv's that control this system. all functioned normally except the purge vsv. i tapped on the valve and re tested. it is now functioning. recommend starting by replacing this vsv as it will likely stick again. It was mentioned the guest was concerned about the charcoal canister. However the codes present are not the typical codes associated with a flooded canister. I would recommend starting with the known bad component.
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Seems to comport with what @Sykoslug just posted.
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- #1,008
There was and guy who wrote about the EVAP VSV (on intake), on other Toyota/lexus, other than 4.7L 2UZ. He was finding these Toyotas, in salvage yards, in relatively good condition. He felt, they were ending up in salvage yard due to fuel issues (boiling). What he showed, was charcoal in the VSV and its hose clogging them.
VSV is for sure, a component that needs testing.
Shielding is for sure helpful, especially in rigs with under armor//belly pan. It should not be necessary, in stock rigs. But again, helpful, in them as well.
But if CC flooded, it will need replacing. Once flooded, they just keep getting worst. Eventually they get so bad, just driving around town, engine will stall or RPM will get very low and erratic. They'll be a smell of vapor, in most cases, will be like very old stall gasoline smell.
VSV is for sure, a component that needs testing.
Shielding is for sure helpful, especially in rigs with under armor//belly pan. It should not be necessary, in stock rigs. But again, helpful, in them as well.
But if CC flooded, it will need replacing. Once flooded, they just keep getting worst. Eventually they get so bad, just driving around town, engine will stall or RPM will get very low and erratic. They'll be a smell of vapor, in most cases, will be like very old stall gasoline smell.
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Replacing purge vsv did not alleviate the fuel smells. Still getting same error codes as before.
Possibly related… maybe red herring… but after replacing the purge vsv… drove the LX from Omaha to Evergreen… filled up before leaving Omaha no problem at the station … filled up again just outside of Denver… no problem at the station
Drove all over CO all last week… even did the Barbour Fork trail near Idaho Springs. Filled up the 40 gallon tank to head back home and heard something leaking. Looked underneath and saw fuel streaming down on the ground right off tank. Looked like about a pint poured out and then slowed to a drip before stopping completely.
Not sure if this is related in any way to the issues I’ve been having. Might be something shook loose on the trail? Might just be a one off where the pump I was at didn’t shut off and overfilled the tank? Idk but was definitely a little unnerving getting back on the road for an 8 hour trip after that lol.
Anywho, we got home without any problems. The shop is gonna look at it again next week and see what’s what.
Turns out the hose from tank to canister was torn. There was enough slack to cut off the torn end and reattach. Now the only gas smells are from the dogs.
Not related to tank pressure, but my two bob on the fuel smell I posted on here earlier.
With mine I was leaking a LOT of fuel from fuel pressure pulsation damper, actually making a puddle under the vehicle when I finally found it.
Its located at the back of the fuel rail on the FZJ105, UZJ100 and probably other models.
My post is here:
forum.ih8mud.com
With mine I was leaking a LOT of fuel from fuel pressure pulsation damper, actually making a puddle under the vehicle when I finally found it.
Its located at the back of the fuel rail on the FZJ105, UZJ100 and probably other models.
My post is here:
Strong fuel smell in LC100
I have a 2005 LC100 with 299k miles. I drove it from Aspen to Denver last week and when I stopped I noticed a very strong fuel smell emanating from the vehicle. I don't have any codes and I am concerned it may be a fuel leak. I don't normally smell fuel when I drive it around town but it...
forum.ih8mud.com
I replaced the charcoal cannister recently and have noticed that my tank is no longer making pressure release sounds at the gas cap.
I’m afraid to ask how much that cost
I think the one I purchased was like $35 on sale on Amazon. It’s an easy job (at least on a FZJ80), even for the mechanically disinclined (like me).
Around $300 for oem
Thanks
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- #1,017
Now make sure, whatever caused CC to go bad (saturated) is corrected.
If it was just a case of miles, you should be around 1 million or more miles now
.
This has been on my mind. Do you know any typical causes for it to go bad?Now make sure, whatever caused CC to go bad (saturated) is corrected.
If it was just a case of miles, you should be around 1 million or more miles now
- Thread starter
- #1,019
SEE OP!
Year 98-02 or 03-07 have some differences.
2005 here. Could've been overfilled at some point as your OP suggests.