92 S10 4.3L Random Stall after reaching normal operating temp. Most of the time starts right back up. Replaced MAP Sensor, point, plugs, dist cap, wires. Gives code 42 and 43.

Have you checked the fuel pressure? It should be 9 to 13 lbs. Could be the fuel regulator in the TBI or the fuel pump getting weak. Also on the codes, is the brown wire behind the glove box plugged together for the timing advance? This is what the codes are...42, ELECTRONIC SPARK TIMING (EST) CIRCUIT... 43, ELECTRONIC SPARK CONTROL (ESC) CIRCUIT

Well you may have a bad Ignition Control Module or ignition/pickup stator or a bad knock sensor or bad connections to them or shorted wiring to them or the distributor is worn. Test all those along with the (EST) Electronic Spark Timing. May need a repair manual to do so it very in-depth to explain here, May can find some of those test already posted to the net.

I will check out both of the above answers and post results. Thank You!