1993 Other Chevrolet Models backfiring

Engine Performance problem
1993 Other Chevrolet Models 6 cyl Front Wheel Drive Automatic

chevy lumina apv. Runs fine until it warms up then backfires upon acceleration. Last time it backfired then stalled. When trying to restart it flooded out. Waited about 20 min to try and start it again. It still would not start and had a very strong smell of gas and I did not touch the gas pedal while trying to start it.