I have a 6cyl Optima that recently has begun having trouble starting after fueling? Any ideas?
Is the Check Engine light on?
Do you have the habit of trying to get every penny of gas in the tank when you full up, or do you stop when the pump shuts off.
If you force more fuel into the tank…after the pump shuts off…you can saturate the charcoal canister and it can make for hard starts.
It’s one thing to “round” the pump up to the next dime, but forcing another 45 cents worth, is a no no with cars built after the early 1980s
It’s impossible to pack a gas tank to the point where it saturates the charcoal canister.
The EPA knew there were morons out there that would try to do so.
So since OBDII was introduced, the EPA demanded a method be devised to prevent that from happening.
So the Onboard Refueling Vapor Recovery system has a component called an Overfill Check Valve.
This valve not only prevents overfilling of the gas tank, it also acts as a roll-over valve.
Interesting. Do you have a link or something to confirm that the EPA requires an overfill check valve since the switch to OBD2? That’s not something I was aware of. I can find all kinds of information on overfill prevention valves for underground storage tanks but not for cars.
Thanks. I know the EPA requires a vapor recovery system when refueling but you mentioned that “So since OBDII was introduced, the EPA demanded a method be devised to prevent that (fuel from saturating the canister) from happening”. That Wikipedia article doesn’t show that - it just describes a vent/rollover valve but has a dead link. I was looking for something from the EPA or a more credible source that confirms that it’s impossible to saturate a vapor canister.
It provides a method of controlled escape for gasoline vapors during the refueling process. It has a mechanism which closes the vent in the event the vehicle rolls over, to prevent spilling of VOCs or fuel in general. It also acts as a fill limiter.
What’s so hard to understand?
Now if you want to go to https://www.epa.gov/, and look up the actual regulation, be my guest.
Easy. Where does that say it prevents fuel from entering the canister? Where does it say the EPA requires this device on all OBD2 vehicles?