Does anyone know what would cause the tank on my 71 Grabber to pressurize? If I pull the cap it releases a ton of pressure. I think it's even making the car run poorly. Thanks!
Vent tube plugged? It's on the firewall, passenger side. Connects to the charcoal can and goes all the way back to the tank.
The gas cap has a one way check valve in it to prevent a vacuum build up as fuel is being used. The vapors are supposed to go through the carbon canister, to the air cleaner to be burned. if you now just have the metal tubing sticking under your hood, your venting gas fumes directly in your engine compartment. Not a good thing to do. You can also drill out the check valve in the gas cap so it will vent both ways.
Take the cap off and look at the backside. You will see a small hole in the center. You can suck air in through the hole but you cant blow air out through it. Just take a drill the same diameter as the hole and drill out the check valve. Its only plastic so it drills out easily. Just be careful you dont drill all the way through the cap.
