What would cause a 2000 Blazer to shut off mid-trip then keep it from starting again?

check for spark at a plug wire, a hot coil will break down when hot ,heat with heat gun and test for spark , hold peddle to floor if flooded, it shuts injectors off that way

try replacing the spark plugs with what the manufacture calls for that vehicle. I ran into a similar problem a few years back had fire on the plugs but wouldn't run got the plugs it called for that vehicle and it fired right up. good luck it worth a shot for the money.