Intermittent problems can be a real pain in the butt. You could have had a vapor lock in the fuel line, intermittent no signal from the crank sensor. PCM might be dying. Without it doing the thing and being tested on the spot all you're going to do is shot gun it and throw parts at it until it stops doing it......if it even ever does it again. The list is as long as I am tall 6'9" where do you want to start?