So let’s see if the gas has water in it. Take a piece of garden hose and siphon somne of the gas out of the tank. I’d drive it around the block and replicate the problem by hard and frequent braking to mix the gas and water up a bit. Then siphon a glass jar full and let it settle. Gas and water don’t mix well . . . and you’ll be able to see if you have bad gas. Easy-squeezy. If you DO have bad gas . . . gotta sipohn as much as you can out, dispose of it properly, and re-fill with clean gas and drive it. Maybe change fuel filter(s), it’s time anyway. A bottle of dry-gas will help. If it’s NOT bad gas . . . look at the other posters responses about the ignition system. BTW . . . I had a tank of bad gas once, lived at that time in the flatlands, only time the car sputtered was at stop signs and going around 90 degree turns. Weird. But easy to check. Good luck! Rocetman