Transient speed- and transient load-based compensation of fuel injection control pressure

An engine (10) has a fueling system that uses hydraulic fluid to force fuel into engine combustion chambers via fuel injectors. Pressure of the hydraulic fluid is determined by a steady state strategy (ICP—DES—1) and a transient strategy (34, 36) that develops transient data values to account for certain transients in engine operation by processing engine speed data and data representing rate of change of engine speed, and data representing engine fueling to develop sub-strategy data values (ICP—FF—TS, ICP—FF—TL) for a transient component. The data values ICP—DES—1, ICP—FF—TS, and ICP—FF—TL are algebraically summed to develop a data value (ICP—DES—2) for a transient-modified desired hydraulic fluid pressure that is compared with a data value for actual hydraulic fluid pressure (ICP) to develop a data value for an error signal ICP—ERR. The data value for the error signal is processed according to a closed-loop strategy to develop a data value that controls the hydraulic fluid pressure.