My van surges, cuts out, started backfires

Checking fuel pressure would be my first step when diagnosing your 2001 Chevrolet Venture. For that you will need a pressure gauge. Fuel pressure should be 52 -59 psi with the pump running and the engine off. If pressure is low, chances are you will need a fuel pump. If pressure is OK next things to check would be crank sensor/ignition system and mass air flow sensor.