I don't mean by burning it. Today I had the car sitting at idle for about 15 minutes. Car was sitting flat in the driveway. I noticed gas pouring out of the gas door. I have about 50 miles on this fill up so I know its not over filled. Took the cap off and it was still leaking out. There wasn't alot of pressure when I removed the cap. Ive been into Honda's for going on 15 years and have never seen this issue before. The car has the OEM cap but the rubber is torn in one place. This still shouldn't cause the issue of it pouring out. Maybe someone else has had this issue and can give me some ideas. I have been smelling gas fumes strong for awhile now figured it was from the previous owner removing the charcoal canister. Looks like it has been leaking out for awhile because the paint under the gas door is faded a little. Car has a DOHC ZC swap in it but that should be irrelevant.

 

i've never heard of that either. i'd like to find out what would cause this too.

 

did the cap off the fuel vent hose when the took out the canister?

 

You underestimate the amount gas expands with temp. You have to remember that at 99% of gas stations, the gas tanks are underground and very well insulated, they normally sit at around 52-58 degrees, year round. If you fill up, and go park your car in the sun, its very possible for the gas to overflow out of the tank. It's happened to me personally before.

 

The vent that is suppose to goto the charcoal canister is just open under the hood.

Wasn't really that hot here today maybe 75 but the car had been in the shade for about 2 hours. It wasn't leaking any fuel till the car idled for awhile may have been 30 minute. I was waiting for the fan to kick on .

 

The tank isn't venting right. It's getting pressurized and pushing it out the cap. That’s why it happed when u were just sitting there idling(running). Check the vent line from the gas tank to the charcoal canister make sure there is nothing plugging it if there is take it out and put a filter on it. The only way your going get rid of the gas smell it too put the purge valve and charcoal canister back in the car.

 

The vent going from the tank to the engine bay is clear. I blew thru the hose and it is clear and going into the tank. Like I said the cap did not have any pressure on it when I removed it. Ill replace the cap and see what happens.

 

Does your car produce boost at idle? I'm not seeing how the purge system could possible pressurize your fuel tank. I could see how sitting there idling could warm your fuel though. The fuel traveling through the rail and from the pump itself.

I did the math, and with the difference of 50 degrees F, 12 gallons of gas will expand by about .7 gallons.

I still think it's possibly the answer.