Abstract: A system and method of controlling the rate of flow of supplemental fuel to an air intake received by an engine. The operating characteristics of an engine are sensed. An operational window is determined. The operational window defines the optimum operating characteristics of the engine. A memory storage device stores a control map. The control map defines an amount of supplemental fuel to add based upon ranges of operating characteristics of the engine. It is determined whether the sensed operating characteristics are within the optimum operating characteristics defined by the operational window. A control signal is formed to vary the rate of supplemental fuel flow through a trim valve based upon whether the sensed operating characteristics are within the window and according to the control map.

Abstract: A system and method of adjusting the rate of supplementary fuel flow to an engine while monitoring the operating characteristics of an engine. The amount of pressure to apply to a regulator valve is determined based at least in part upon the operating conditions of the engine and information included in a stored fuel grid.