Abstract: A gaseous-fueled reciprocating internal combustion engine includes a carburetor having a throttle valve that is controlled by a speed governor. A proportional fuel control valve is disposed intermediate a fuel supply and the carburetor, and is controlled by an air fuel computing device. The computing device generates a control signal to adjust the fuel control valve based on a governor sensed variable indicative of engine speed, sensed engine torque, a governor output signal from the governor indicative of an opening position of the throttle valve wherein 100% corresponds to a wide open throttle position, and 0% corresponds to a closed position, and a lean combustion control map containing predetermined set point values stored in memory.

Abstract: A parametric emissions monitoring system for monitoring stationary engine/compressor units coupled to a pipeline provides, in a reciprocating embodiment, reliable and accurate determinations of emission levels for NO.sub.x, CO, and total hydrocarbons (THC) from an emissions matrix primarily as a function of engine speed and engine torque. Validation of the determined emissions level is provided by comparing the values of a set of actual engine operating parameters with a respective value in a set of calculated engine operating parameters to determine whether the deviation of the actual operating parameter from the expected operating parameter is within a defined range, and thus whether the engine is operating within a defined control envelope. Each set of engine operating parameters includes spark ignition timing, fuel rate, and air manifold pressure.