Hyundai Santa Fe won't start after filling with gas?

I have a 2005 Hyundai Santa Fe, about 128,000 miles on it. For the past 5 months or so, the engine simply won’t start after filling with gas - and only after filling with gas. I’ve tried filling partially from near-empty, as well as filling full from halfway or more full…it consistently won’t start up after filling with gas.

After turning the ignition, the engine will turn over, but quickly quits. Lately it’s had more trouble turning over at all. To get the car moving, I need to actually feed it gas with the pedal, and “simulate” idle. Even after a couple of minutes, if I let off the pedal it dies right away…as if gas just isn’t getting to the engine on its own.

In order to get the car moving, I just have to keep feeding it a bit of gas while shifting to drive (and stepping on the brake), then I give more gas and let the brake go almost as if it’s manual-transmission…off it goes.

Oddest thing: as soon as that happens; as soon as the car moves forward (even just to get out of the gas station), everything’s back to normal. The car idles healthily at the next stop, as if nothing happened.

Any idea what’s going on here??? No check-engine light, no diagnostic codes come up with a scan. Same results on warm or cold days. Most recent maintenance on it was new spark plugs almost a year ago (doesn’t seem related).

Of course, the only time it DID fire up normally after filling with gas was when I had the mechanic with me in the car!

Try this at your next fill up. Start with the lowest setting on the nozzle and let the pump run until it shuts off the nozzle. Remove the nozzle and hang it up. Don’t attempt to add any more fuel. Start the car and drive away. If the vehicle runs normally…keep using that procedure for all subsequent fill ups. Topping off or over-filling vehicles in this day and age causes all kinds of problems that can cost you money.

Is your check engine light on?

I would think that your Evaporative Emissions Purge Valve is stuck open. That valve should normally closed when the engine is off. If it is sticking open, the force of the incoming fuel to the gas tank can cause fuel vapors to travel through the open valve into the engine, essentially flooding it. It may then be necessary to hold the gas pedal to the floor when starting the engine and revving it a few times to clear the flood and then the engine operates normally again.

+1 @asemaster - purge valve.

Concur, it does sound like a purge valve problem, a common complaint here. The only other thing I can think of is to try an experiment of loosening the gas cap when then happens, see if that helps or not. Don’t drive the car with a loose gas cap though, just something to try as an experiment to debug the problem…