Engine control system with cylinder identification apparatus

Abstract

A four-cylinder engine control system (10) for controlling the functions of ignition or fuel injection is disclosed. The control system includes cylinder identification apparatus (30, 50, 60) which operates in conjunction with a rotary member (11) rotated by the engine crankshaft having timing projections (14, 17) corresponding to specific rotational positions of the crankshaft. A pair of fixed sensors (20, 21) sense the passage of the timing projections and provide corresponding signals to an engine timing calculation and control circuit (40) which provides control signals that are sequentially selectively routed to control ignition and/or fuel injection of the engine cylinders in a predetermined sequence. One timing projection (14) comprises two individual radial extensions (15, 16) whereas another comprises a single extension (17). Cylinder identification apparatus utilizes sensor pulses (200, 201) provided by the fixed sensors to distinguish between the passage of the pair of extensions versus the passage of the single extension and provide a cylinder identification pulse (207) indicative of the rotational position of the engine crankshaft. This is accomplished by a first pulse reject circuit (60) which provides an output when one of the sensors produces two pulses prior to the other sensor producing a subsequent pulse. This output is then utilized to initialize the sequential gating of control signals to cylinder control apparatus.