Q: Obd codes 33,34, and 43 what does this mean? 1993 Chevrolet K1500

Hi - the diagnostic trouble codes you mention are: 33- Manifold Absolute Pressure circuit/sensor malfunction: wiring open circuit/shorted circuit to positive, hose blocked/leaking, MAP sensor, 34- manifold Absolute Pressure circuit/sensor malfunction: wiring shorted to ground, 42- ignition control module circuit problem (running on default timing curve). These collectively sound like engine wiring harness issues, or perhaps a bad engine to chassis ground, or engine/chassis to battery ground issue. I recommend a running rough inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.