Abstract: An electronic control fuel injection system for a spark ignition internal combustion engine is described which controls air flow rate as function of fuel flow rate by transmitting an operator's depression stroke of an accelerator pedal to a fuel selecting mechanism which determines the fuel flow rate, applying a signal representative of the selected fuel flow rate to a computer together with various correction information, calculating by the computer from the selected fuel flow rate and correction information, the optimum air flow rate, and determining the opening of a throttle valve from the calculated result via a throttle valve servo mechanism. The invention is particularly useful in eliminating hesitation of an automobile while attaining both fuel economy and low harmful exhaust emissions.

Abstract: A circuit device for driving an electromagnetically movable unit at a high speed with a single power source such as a battery comprises a plurality of power transistors for inverting the polarities of the input power, a pair of control transistors connected via a NOT element to the control circuit of the transistors for turning then alternately on or off, and instantaneous double voltage generator connected to the output circuit of the power transistors. Rapid responsiveness of the circuit device can be obtained by magnetically driving the movable unit in both one way and return way without a conventional return spring.

Abstract: An electronic control fuel injection system for a spark ignition internal combustion engine is disclosed which controls air flow rate as a function of fuel flow rate by converting an operator's depression of an accelerator pedal to an electric signal, applying the signal to a computer which preferentially determines the fuel flow rate and then the air flow rate, and feedback controlling the air flow rate by using the determined air flow rate and an actual air flow rate sensed by a pressure sensor provided at the upstream and downstream sides of a throttle valve and/or a throttle opening sensor. The computer also receives signals representative of the fuel line pressure and the air pressure in a region adjacent one or more injectors and uses this in adjusting the supply of fuel to the injector(s) to obtain a predetermined constant pressure difference thereacross. A unique digital flow control valve may also be used to precisely adjust the air flow rate.