1998 Hyundai Elantra Car refuses to start after rain. Sputt

1998 Hyundai Elantra 4 cyl Front Wheel Drive Automatic

Hello. My 1998 Hyundai Elantra has a few problems that I need help with.

1. Occasionally, especially after rain, my car doesn't start. It turns over, but just doesn't want to fire.

2. My car sputters very badly. When I first put my car into gear, reverse or drive, my car sputters VERY badly and sometimes stalls. It seems the more gas I try to give it, the worse it becomes.

Any help you can give would be much appreciated. Thank you.