Patent ID: 6244248
Filing Date: 2001-06-12
Classification: F02D

Abstract:
A four-stroke fuel injection internal combustion engine comprising:a plurality of cylinders with pistons linked to a crankshaft, an exhaust conduit, at least one engine operating condition sensor and an exhaust gas sensor in an exhaust conduit, and an engine management system that includes a timer and fueling controller for controlling the air/fuel ratio for at least one cylinder, the engine management system being arranged to receive from the at least one sensor respective signals representative of engine operating conditions including exhaust gas condition, wherein the engine management system further comprises a processor arranged to verify the engine cycle by first altering the air/fuel ratio for one cylinder relative to the other cylinders, then timing a time delay until a signal is received from the exhaust gas sensor indicating a change in exhaust gas condition attributable to exhaust from the one cylinder, and then comparing this delay against an expected delay according to the engine operating conditions.