Abstract: A controller for an internal combustion engine has a hydraulic valve characteristic changing mechanism for changing valve operating characteristics of suction and exhaust valves; a valve system provided with a hydraulic valve phase variable mechanism that changes the phase; a map that stores a fuel injection quantity and an ignition timing in response to the valve operating characteristics; and delay time setting means for setting a delay time required to complete changeover of the valve operating characteristics, based on operating oil properties detected from behavior of a valve phase variable mechanism, to change the map after the delay time has elapsed. Thus, a valve operating characteristic changing timing coincides with a map changing timing to thereby achieve an improved performance of the internal combustion engine.

Abstract: When the valve operating characteristic changing control for converging the deviation between the actual cam phase and the target cam phase of the internal combustion engine is carried out, the responsiveness and the convergence can be reconciled independent of the operational state of the internal combustion engine. A valve operating characteristic changing mechanism capable of continuously controlling the cam phase is provided at an end of a cam shaft, driven through a crankshaft by a timing chain. When the deviation between a target cam phase and an actual cam phase is equal to or smaller than a threshold value, the valve operating characteristic changing mechanism is controlled in a feedback manner. When the deviation exceeds the threshold value, the valve operating characteristic changing mechanism is controlled in a feed-forward manner with a basic operational amount, thereby reconciling a responsiveness and a convergence.

Abstract: A valve operating control system for an internal combustion engine is provided which includes a cam switching type first valve operating characteristic changing mechanism, and a cam-phase changing type second valve operating characteristic changing mechanism, wherein the responsiveness and the reliability of the valve operating characteristic changing control can be guaranteed, while suppressing the capacity of an oil pump used commonly for both of the valve operating characteristic changing mechanisms.

Abstract: A fuel injection control system for an internal combustion engine includes an ECU which carries out adherent fuel-dependent correction by calculating an amount of fuel to be injected into the intake passage such that a sum of a direct supply amount of fuel directly drawn into the combustion chamber of the engine without adhering to the wall surface of the intake passage out of a whole amount of fuel injected into the intake passage, and a carried-off amount of fuel carried off the wall surface of the intake passage into the combustion chamber out of fuel adhering to the wall surface of the intake passage is equal to a required fuel amount for the engine. The starting condition of the engine is detected by sensors, and operation of the adherent fuel-dependent correction control is limited during the starting condition of the engine.