Fuel metering control system for internal combustion engine

Claim 1

A system for controlling fuel metering for an internal combustion engine having an air intake system including a throttle valve, a plurality of cylinders, and an exhaust system, said system comprising: (a) an air/fuel ratio sensor located in the exhaust system of the engine for detecting an air/fuel ratio of an exhaust gas of the engine; (b) engine operating condition detecting means for detecting engine operating conditions including at least engine speed and engine load; (c) basic fuel injection quantity determining means for determining a basic quantity of fuel injection TiM-F, Tcyl for individual cylinders based on at least the detected engine operating conditions and a change in an effective opening area of the throttle valve; (d) a catalytic converter installed downstream of said air/fuel ratio sensor; (e) a feedback loop for calculating a feedback correction coefficient KFB to correct the basic quantity of fuel injection such that the detected air/fuel ratio KACT detected by said air/fuel ratio sensor is brought to a desired air/fuel ratio KCMD; (f) output fuel injection quantity determining 5 means for correcting the basic quantity of fuel injection based on the feedback correction coefficient, to determine an output quantity of fuel injection Tout; (g) fuel adhesion correction means for determining an adhered fuel correction based on a quantity of fuel adhered on an intake manifold wall of the engine; (h) output fuel injection correcting means for correcting the output quantity of fuel injection based on the adhered fuel correction; and (i) fuel injector means for injecting fuel in the individual cylinders of the engine based on the corrected quantity of fuel injection.