Why don't you ask over on the Cars Forum? It's under "Miscellany."

It could be something as simple as a loose or worn gas cap. Make sure your cap clicks 2 or 3 times when you put it on.

Just a note, you're never supposed to leave your car running while filling up with fuel.

Mimi boo is correct. It's illegal in most states. Don't your stations have "turn off engine" signs? Right along with the no smoking signs?

Today's fuel systems are pressurized so the gas cap must have a good seal for performance.

my first thought was i think there is a gas cut off switch that cuts the engine when the pump nozzle is inserted. there was a recall yrs ago on my grand cherokee involving the lever that is pushed in when you insert the gas nozzle. ~ liz

"If any of you know a mechanic could you please ask them why this would happen?"

Why can't you ask your mechanic?

Check on the *Cars Forum* here. They are very knowledgable and helpful.

Google for the answer. There are dozens of helpful and informative automotive maintenance sites.

And as other have said.....Don't fill while the engine is running. I'm surpirsed the gas station atendants have not come out to reprimand you.

leaving the engine running will not hurt anything,including the pumps..thats a fallacy..but anyways..it sounds more along the line of an intake issue or something to do with the injectors

tell him to either put gasline anti freeze into it(if you are in a cold state) OR to get some of that engine performance stuff that goes in with a full tank to clean our the intakes.

It could also easily be a carbureator issue..sounds liek it could be carboned up and needs to have the crap blown out of it....stalling is usually simple enough to fix

The answer is simple.
When you remove the gas cap, the pressure in the gas tank goes down and sensors react and cut off the engine.

The sensor doesn't know that you are refueling at a pump with the engine running.

Thanks everyone for the suggestions. As always I appreciate it.

Samkaren
your resident DJ

Well those were some entertaining responses. Now here's a real answer: You need to stop pumping when the pump shuts off, instead of trying to squeeze that extra fuel in and "top it off". You're flooding the evaporative emissions cannister by doing that, and then flooding the engine upon startup.

P.S. There is no carburetor on a 2004 model, no switch that turns the engine off when the gas pump nozzle is inserted, and no sensors that "react and cut off the engine" when the gas cap is removed.

That's true Chad but she never said it happened after topping off. She said when running or after filling she would get stalls or hard starts. It seems unlikely the system would be flooded while running.

Now it could be a bad Evap Purge Valve on the canister. Wouldn't matter then if the car was topped off or not. I'd try the gas cap first though. Cheaper to deal with.

She said: "If we turn the engine off while filling up it takes 2-3 attempts to start it." Since most people incorrectly keep filling after the automatic shutoff, it means the same thing.
The reason it stalls when left running is simple. As the gas rushes into the tank, it causes cavitation and the engine stalls when an air pocket forms around the fuel pump pickup. Another reason, in addition to the safety concerns, not to leave it running when filling up. But people are stubborn and believe the rules are not meant for them.

Thank you Chad and Wildchild. I'm going to pass this info to my DH Since I haven't pumped gas in nearly 7 years. Yes...it's true....DH fills up the truck when it's low. Last time I pumped gas they had the old fashioned handle that you lifted up and you had to go inside the station to pay.

SamKaren
your resident DJ