Abstract: A flow control system for use in a compressible fluid-fueled internal combustion engine includes a fluid metering device comprising a plurality of fluid lines for communication between an inlet fluid manifold and a metered fluid manifold. Bistable valves of various orifice sizes are provided, one in each of the fluid lines except for at least two lines, which are provided with pulsing valves. The device also includes sensors for determining parameters of the inlet fluid sufficient to determine potential mass flow of fluid through each of the valves, and valve controls for activating valve actuators to open the valves in combinations and for time intervals to give a desired total mass flow of fluid through the valves.