The Erratic Staller

I am driving a 1999 Honda civic lx, 1.6 liter.

I have been experiencing stalls 20 minutes after car has been started. Once the car has stalled, it will take about 10min to restart.

I have already replaced my distributor, and ignition switch. There are also no check engine lights on. And I have already completed a full ob2 diagnostic which came up with no codes.

I have already put $200+ into this project, and its starting to bust my bubble.