1996 Camaro 3.8 V6 RPM drop/stall problem

My son’s Camaro intermittently drops RPM (to zero on the tach) for a split second, or stalls if at low RPM. This can happen after a few minutes of driving, or much longer. Sometimes when this problem occurs the engine will not start. It cranks but doesn’t catch. There are no codes on the OBD.

When in the failed state, I can hear the fuel pump run when I turn the key to the “on” position, and there is fuel under pressure at the fuel rail (manual check, not with a fuel pressure gauge yet).

If you let it sit for some time (30 minutes?) it seems to start just fine.

I am a novice, so what is the best way to go about diagnosing this problem? As always, any help would be appreciated.