sabresfan

For about a month now my fuel tank has been spitting out gas from the gas cap and runs down the side of my car and smells like gas while driving. It only seems to do it when the gas tank is more than 1/2 full and it will happen at random times (esp when its really hot out)

what can i do to prevent it? i replaced my fuel filter and did an entire seafoam about 2 months ago if that might have caused something. i'm thinking the fuel tank pressure valve possibly?

also my fuel gauge has never worked haha

Injuneer

Two possible causes - cap gasket has failed (it's a sealed, unvented cap), or you have excessive pressure in the tank, possibly due to a faulty EVAP system or faulty pressure/vacuum relief valve. Excessive pressure can also be caused by the fuel heating up, which can be related to a failing fuel pump.

Moving to "Fuel and Ignition" forum.....

sabresfan

how do i test the evap system?

and where is the pressure relief valve? is it easy to get to? my haynes manual isnt the greatest resource for this issue

Injuneer

There's a pressure control valve that releases fuel vapor to the canister, and that is up high, between the tank and the canister in the driver's rear fender:

Courtesy of Shoebox

http://shbox.com/1/evap_system.jpg

In the event the tank pressure is not vented through the EVAP system, there's a pressure/vacuum relief valve that prevents tank damage due to over-pressure:

sabresfan

how do i test the fuel tank vent valve? im pretty sure thats the issue

Injuneer

I'll check on another forum. Someone tested his for both pressure and vacuum. But I don't remember the numbers.

But the vent valve is only intended to prevent damage to the tank, in the event the pressure control system fails, and pressure or vacuum becomes excedingly high. The question would be why isn't the tank venting through the EVAP canister?

Do you have an axcessive pressure release when you open the cap?

sabresfan

when i open the cap i can hear the pressure being released but its always been that way and i thought it was normal for lt1s