Abstract: The throttle valve position is sensed and the effective cross sectional area of the induction passage determined via table look up. The value thus derived is divided by the engine speed. A basic air induction quantity is then determined via table look up and subsequently modified using a correction coefficient to allow for the effect of engine speed on the amount of air inducted into each cylinder. The effect of injector position (viz., MPI/SPI) is taken into consideration and values suited for both generated in given embodiments. In the event that the maximum induction vacuum is limited by a BCD valve or the like, an embodiment anticipates the change in induction characteristics based on the engine speed.

Abstract: The throttle valve position of an engine is sensed and the effective cross sectional area of the induction passage is determined via table look-up. The table is recorded in terms of three parameters. The value thus derived is divided by the engine speed of alternatively a product of the engine speed and the engine displacement. A basic air induction quantity is then determined via table look-up and is subsequently modified using a correction coefficient to allow for the effect of engine speed on the same. The effect of injector position (viz., multi-point injection/single point injection) and/or the provision of a swirl control valve can be additionally taken into consideration via the use of suitable algorithms or additional two and three parameter system tables. If an idle control by-pass passage is provided, the effect of the opening degree is considered when determining the effective cross-section of the induction passage.

Abstract: In order to ensure that idling control is assuredly provided when the engine is subject to cold starts and the like, a solenoid which controls the modulation of a pressure signal via which a vacuum operated servo unit is controlled, is arranged to be fed an energization signal having a maximum energizing effect when a parameter indicative of the engine being started or having just been started is detected.

Abstract: A fuel pump control system controls the operating speed of the fuel pump to control the fuel pressure in a fuel supply circuit for a internal combustion engine. The control system includes a main control circuit constantly connecting a fuel pump driver to a vehicle battery which acts as a power source and a normally-open auxiliary circuit. The main control circuit adjusts the power supply to the fuel pump driver to adjust the operating speed of the fuel pump to either a first maximum or a second minimum speed. The auxiliary circuit establishes electrical communication between the fuel pump driver and the battery when a demand for increasing of the fuel pressure in the supply line and thus for enrichment of the air/fuel mixture beyond a predetermined value is detected on the basis of one or more preselected engine operating parameters.