Driving home from my sister's the other day pulled over at a pay phone to call my wife and when I tried to start the car again, it wouldn't. Stuck around and tried on and off for about 45 mins, before I gave up. Went back the next day with friend, tried again and it started right up. Later that day it would not start again. This time I waited 15 minutes and it started. Then I was waiting at a light and the car stalled and would not start. Turns over no problem, strong battery just won't start.
Any ideas???
PS: New plugs, air filter.