ncoppola- it's the evaporation valve. it sits usually directly at the fuel intake underneath. it's actually just a simple pipe with a ball in it. the gravity pulls the ball down and closes the pipe. if the airpressure increases in the tank, for example when you get gas, the air pushes the ball up and the air comes out there. the hose routs to the front to the active charcoal filter- there is another solenoid valve. one or both can be broken. that's usually the reason for spitting- the air can't go out fast enough and the backlash pushes the gas back out.
What I think about smoke test....you don't wanna know.
What I think about smoke test....you don't wanna know.