Patent ID: 7066143

Claim:
A fuel injection control system for a medium-speed compression ignition diesel engine for powering a railroad locomotive, the engine being operative in predetermined throttle notch settings and including at least one power cylinder, a piston in the cylinder, at least one fuel injection pump, an engine air intake for flow of combustion air to the cylinder, and at least one fuel injector connected to said fuel injection pump for injecting fuel into said at least one cylinder at a predetermined timing relative to a position of the piston in the cylinder, said fuel injection control system comprising: a barometric pressure timing controller connected to said fuel injection pump and fuel injector, said barometric pressure timing controller controlling fuel injection timing based on changes in barometric pressure; a first memory in communication with said barometric pressure timing controller for storing nominal values of a parameter of the engine intake air, with at least one value of said parameter for each set of a plurality of sets of values of engine performance characteristics, where each set of values of engine performance characteristics corresponds to a throttle notch setting, and where said nominal values of said engine intake air parameters are measured at a nominal barometric pressure; a sensor in communication with said barometric pressure timing controller for sensing an instantaneous value of said engine intake air parameter; and at least one engine performance sensor in communication with said barometric pressure timing controller for sensing an instantaneous value for at least one of said engine performance characteristics; wherein said barometric pressure timing controller communicates with said first memory to access a nominal value of said engine intake air parameter corresponding to said instantaneous value of said at least one engine performance characteristic; and wherein said barometric pressure timing controller determines an instantaneous value of barometric pressure based on said nominal value of barometric pressure and the difference between said nominal value of said engine intake air parameter and said instantaneous value of said engine intake air parameter, to provide a signal indicative of changed barometric pressure to control fuel injection timing.