Abstract: In a vehicle speed control apparatus for an internal combustion engine vehicle, in which the first amount of fuel supply required for maintaining the vehicle speed at a desired speed and the second amount of fuel supply corresponding to the amount of depression of an accelerator pedal are separately calculated, the apparatus comprises a selector for selecting the larger of the first and second amount of fuel supply to control the fuel adjusting member, and a modifying circuit for modifying the output data showing the first amount of fuel supply to cause it to slowly change, taking into account the value of the second data showing the second amount of fuel supply just before the second amount of fuel supply becomes smaller than the first amount of fuel supply, whereby the vehicle speed is prevented from being rapidly decelerated when the mode of vehicle speed control is changed from that by the second data to that by the first data.

Abstract: Herein disclosed is a signal processing system for a motor vehicle with high responsiveness to the will of a driver. The output voltage of an acceleration sensor using a potentiometer is converted into a digital value by an analog-digital converter. The nonlinearity of the output voltage is corrected by polynominally calculating the digital value. This digital value is controlled by a central processing unit which processes the digital value to generate an acceleration signal having a linear relationship to the changes in the resistance of the potentiometer during actuation of an accelerator. The central processing unit further includes a memory for storing the acceleration signal at an idling position to determine a calibrated acceleration signal using a ratio of an actual acceleration signal obtained from the accelerator pedal to the stored value thereof.

Abstract: A method of indicating when a shift operation of a manual gearbox is to be preformed includes a step for comparing a detected vehicle speed with a reference vehicle speed which is determined and changed on the basis of a detected engine operational parameter and a step for indicating that the shift operation should be performed on the basis of a result of the comparison. The reference vehicle speed is corrected to a lower speed in response to an increase of a total running time of the vehicle, thereby to maintain the driveability of the vehicle when the running time of the vehicle is short.

Abstract: An internal combustion engine is provided with a fuel injection valve in an intake passage communicated with a combustion chamber and a swirl controlling device for controlling a swirling motion to be given to intake air in a circumferential direction of the cylinder forming the combustion chamber. When the engine load is low, the fuel injection valve is controlled to inject fuel by an amount required for one power stroke a predetermined time after the intake valve is opened and during the intake stroke, and the swirl controlling device is controlled to give intake air a swirling motion. A correction device is provided, which, when the engine is cold, controls the fuel injection valve to start fuel injection before the intake valve is opened and also controls the swirl controlling device to suppress production of swirling motion of intake air.