Randomly shuts off wont restart for 20 minutes

This is a 96 vw passat it started out that about once a month it would ether die wile worming up and not start again or after a short trip it would not fire. That went on randomly for a wile. Now I was going down the road in 5th and it shut off I put it in fourth and it restarted I took the next off ramp and if I pushed in the clutch it would die
But if I kept it revved up to about 3 grand it would keep running eventually it did die in town and I was not able to restart it for an hour and now the check engine light is flashing.
I hope some one has some idea what this might be or at least how to test some of the more likely components thanks Todd