Many things can cause this. If it was sudden, see if it has an inertia-switch for fuel shut-off. Did you recently drive into something? This switch will need resetting if so.
NEW ANSWER: First of all Chevy did not use an inertia switch on there trucks. If you replace the ignition module in the distributor that will fix your problem.
123456
1,8,4,3,6,5,7,2
18436572
your firing order is 165432
Firing Order: 165432 Distributor rotation: Clockwise 1993 Chevy 4.3L V6 Firing order
18436572
18436572 clockwise
See the Related Links for "1993 Chevy 3.1 V6" to the bottom for the answer.
What engine? V8? 18436572
1,8,4,3,6,5,7,2.
Try your tcc solenoid on the transmission
1,2,3,4,5,6 sounds crazy but true