On-board detection of fuel injector malfunction

摘要

The present invention is directed to an on-board diagnostic system for detecting malfunctioning fuel injectors in an internal combustion engine during engine operation. A fuel injector control means is provided for individually actuating fuel injectors operatively connected to a fuel rail. Pressure sensor means are mounted to the fuel rail for sensing transient fuel pressure waves resulting from actuation of the individual fuel injectors and for generating a pressure signal in response thereto. Signal processing means are provided for processing pressure signals from the pressure sensor means and for generating an output signal upon detecting delayed opening or delayed closing of one or more injectors. Utilization means responsive to the output signal from the signal processing means may include, for example, an indicator lamp to alert an engine operator to an impaired fuel injector and/or means for adjusting the timing or duration of the injector actuation signal to achieve the desired injector opening and closing times.