Gas vapor leak?

[syfir]

After driving for about 20 mins yesterday, as I was getting out of my car I heard a hissing noise coming from the gas cap. Is there a vent to release pressure behind the cap or is it leaking? Normal or no?

[mechanicaldj]

not normal

gas vapors are transferred to the vapor canister and held there til the purge valve lets them go into the intake manifold

look for plugged or collapsed vapor lines coming off the top of the tank

[FB71]

bingo^^^

[mechanicaldj]

was his name-o ^^^^

[SIBladerunner]

Also check your cap. It is supposed to hold pressure, if its not then replace the cap. It's also the easiest and cheapest thing to start with

[skimsucka]

i have vapors build inside the car, all hoses / lines seem fine and no cracks in canister. Is it possible my purge valve doenst work anymore and vapors are forced out hoses lines at connection points? somebody help me

[SIBladerunner]

If you hear vapor noise from the cap the cap sounds like its not sealin and the vacuum pressure is pulling from the tank end, try jump the solenoid open and see if you can hear it click. Then check the connectors etc.

[skimsucka]

anyone can help?

[mechanicaldj]

anyone can help?

^^^^ SAY WHAT???? ^^^^^

[syfir]

After Gas cap change, still have issues

So I changed the gas cap and that seemed to solve the problem, or rather the symptoms. Then the other day I was filling up and heard gas vapor rush out of the tank when I pulled the cap off. I think there is an issue at the evap cannister and the new cap is just sealing in the pressure better. So I'm going to look at the cannister this weekend, but am I able to simply vent the tank fumes to the atmosphere? What I was thinking of doing was capping the nipple on the evap cannister for the gas tank hose and letting the tank vent to the outside air. I know this is not emisison friendly, but other than that, are their any drawbacks to this setup?