97 Toyota Corolla leaking gas out of vapor canister

toyota
corolla

#1

The fuel filler vent line rotted off so I had the gas tank and fuel pump replaced in September. Drove the car for 2 months without a problem until last week.
The car lost power then stalled. I smelled gas and found that there was a large amount of gas pouring out of the bottom of the vapor canister.
I bought a new one (very expensive for a plastic can) and put it on. Drove the car a couple days and then it happened again.
Someone told me not to over fill the tank but I never did. In fact, this doesn’t happen right after I get gas. Its a couple days after I get gas that it happens.
I had two different auto mechanics look at it and neither one of them could figure it out. Next stop is the dealer unless someone has a good suggestion.
(other than don’t smoke when you drive) ha ha.


#2

I’m curious weather the gas lines got crossed when the new fuel tank was installed. There are three flexible lines to the tank. One is the pressurized fuel line from the fuel pump. The second is the fuel return line from the fuel pressure regulator on the engine. The third is the tank vent line that only covers a hole in the top of the tank. The return line extends to the bottom of the tank, near the pump. The vent line uses engine vacuum to suck the vapor out of the tank. So if the return line and vent line were swapped, the vacuum would suck raw gas from the bottom of the tank into the charcoal canister, and the fuel return would still drop gas back into the tank, just from the top, not the bottom.


#3

but why didn’t I have any problems for two months? I would think this would cause the problem immediately. Could it be that a line recently got plugged or pinched? I will check the lines like you suggested. Thanks


#4

For one, the vacuum to the canister is not full vacuum from the engine, but regulated down to a small amount. It is also not a constant vacuum, but switched on and off by the purge valve when the computer senses the right conditions. And, finally, the charcoal canister can hold a lot of raw gas before it pukes up like that. With so much raw gas in the system, the purge valve may also be damaged, allowing too much vacuum into the system now.

I’d check those lines to the tank first, then back check the evap system, charcoal canister, and purge valve for residual damage.