A closed-loop control system controls the timing and amount of water injected into a combustion chamber of a homogeneous charge compression ignition diesel engine to regulate the start of combustion during the compression stroke or early in the expansion stroke of each combustion cycle. A sensor is used to detect the start of combustion and deliver a signal to an engine control unit to adjust water injection timing and quantity, on a cycle-by-cycle basis, to obtain the desired start of combustion during each compression stroke of the engine. The present invention effectively overcomes the problem of repeatable and accurate control of the start of combustion in diesel engines operating in a homogeneous charge compression ignition mode.
Daniel W. Stewart (formerly Daniel W. Dickey)