Originally Posted by 4x4nala
I thought there was a return line from the canister to the gas tank to prevent that?
No, there is no return line. Maybe you are thinking of the fuel rail return line?
However, your post does bring up a very good point. If your control line (from canister to intake) is stuck open, this can also cause the gas smell you describe. Esentially, the line stays open all the time, so there is applied vacuum at all times and while your gas is sloshing around, the evap line will pick up gas. So check your control which is either vacuum or solenoid operated.
Your evap system design changes things, as modern systems have vent valves and non vented gas caps and what not. But I won't go into depth with that just yet.
That reminds me... What is the condition of your gas cap? Is it the correct cap for your vehicle?