Abstract: During cylinder cut-off in which fuel injection for some cylinder(s) is halted, a variable valve operation mechanism or the halted cylinder is controlled based on an operating state of the engine whereby engine vibration is reduced during cylinder cut-off operation. The variable valve operation mechanism may be controlled based on a maximum internal pressure of a combustion cylinder in which fuel injection is continued during the cylinder cut-off operation.

Abstract: During a cylinder cut-off operation in which fuel injection for a part of cylinders is halted and the engine is run with the remaining cylinders, a variable valve operation mechanism of the halted cylinder which fuel injection is halted is controlled based on an operating state of the engine whereby the engine vibration is reduced during the cylinder cut-off operation. The variable valve operation mechanism may be controlled based on a maximum internal pressure of a combustion cylinder which fuel injection is continued during the cylinder cut-off operation.

Abstract: To suppress vehicle shock upon acceleration or deceleration, an upper guard value (KGUARD) for throttle rate of change is calculated based on parameters indicative of engine and torque transmission operating conditions. A target throttle sensor voltage change (DVVTA) is calculated based on accelerator depression and compared with the upper guard value KGUARD. If DVTTA>KGUARD, the final target throttle sensor voltage for the present cycle is determined by adding the upper guard value KGUARD to the previously calculated final throttle sensor voltage. If DVVTA.ltoreq.KGUARD, the target throttle sensor voltage VTTA is used as the final target throttle sensor voltage.

Abstract: A valve timing control apparatus in an internal combustion engine, designed to improve its controllability by deciding a control value by taking into consideration the number of the internal combustion engine and the direction to which the valve timing is to be changed, said valve timing control apparatus which changes the valve timing by changing the rotational phase of the camshaft with respect to the crankshaft comprising: means for detecting the operating condition of the internal combustion engine; means for deciding an optimum timing of the valve from the operating condition detected; means for grasping the present timing of the valve by detecting a phase difference of the camshaft from the crankshaft; and means for causing the present timing to become the optimum timing, wherein there is further provided means for discriminating the direction (advance, retard) to which the valve timing is to be changed from a phase difference between the present timing and the optimum timing in order that the change of

Abstract: An apparatus for detecting a rough road running condition of a combustion engine car comprising means for calculating change values of an output rotational speed of the engine, means for calculating an instability of the measured change values, and means for judging the car to be on a rough road when the calculated instability is more than a predetermined amount.

Abstract: Apparatus for supplying high voltage to each spark plug of a multi-cylinder internal combustion engine via a spark coil includes a distributor plate of a unitary construction made of an electrically-insulative resin and having an integral base portion and an integral connector. A plurality of connecting lines are embedded in the base portion. One ends of the connecting lines are electrically connected respectively to spark coils whereas the other ends thereof extend to the connector. The distributor plate and the spark coils can be fixed, as a unit, to the internal combustion engine by a bracket of metal.