Hi all,

I have a question about my 82 T/A with the Cross-Fire motor. Everything runs just fine, but when it's hot outside (above 75 degrees), and I go to fill up my car, I hear a big rush of air either come in or go out when I take the gas cap off. Any idea why?

I was driving my car around last year on a 90 degree day and went to fill up at a gas station. When I did so, a HUGE amount of pressure was released. I think the fuel was boiling in the tank.

Does anyone know what would cause this issue? Car runs/drives fine. I don't have any issues if it's not hot outside.

 

Pressure actually suppresses boiling. But, I doubt it was boiling, anyway.

The charcoal canister is responsible for letting the fuel tank breathe. Make sure all of the vacuum lines going to the control valves for the canister are in good shape, and the vacuum temperature switch on the intake manifold is working properly.

There is also a vent valve for the tank back by the rear axle. But, it's a back-up plan, not the primary vent.

Having said all that, what you describe doesn't sound all that out of the ordinary.