Water gets in the engine when it rains

(Donation Made)1989, Pontiac Grand Am LE, 4cyl 2.5 ltr, 94K miles, auto transmission. The car runs great, except when it rains. Last year the car was parked outside during a all day rainstorm. When I went to start the car, it would rev but would not turn over. The couple of times it did turn over, it stalled immediately. This has happened 2 other times where after an all day rainstorm, it wouldn't start and even after a full day had passed, the engine still wasn't dried out. But by the 2nd day the car would start but giving it hard gas would make the engine "caugh." After another day passed, the engine would run perfectly again.
On other occasions. I would be driving while it was raining and after going over big puddles, water would somehow get in the engine and giving it gas would make it caugh and eventually stall. I would try to start it but it just would not turn over. Until maybe hours later after the rain stopped. Sometimes it would run and sometimes not. Any ideas?