Electronic fuel injection control system for an internal combustion

Abstract

A fuel injection control system that controls the quantity of injected fuel for an internal combustion engine of the type such as a V-8 engine is disclosed. Such fuel injection control system first calculates a basic amount of fuel to be injected per engine revolution T.sub.p (T.sub.p =Q/N .times.Constant Q: intake air flow rate N: engine revolution speed, e.g., rpm), then calculates correction coefficients (COEF, .alpha..sub.L and .alpha..sub.R) on a basis of other various engine operating parameters (e.g., cooling water temperature) and the air-fuel mixture ratio of each bank of cylinders as sensed by exhaust gas detectors and combines either of their numerical results with the numerical result T.sub.p to obtain a pulse width representing an amount of fuel per revolution T.sub.i, and lastly opens either or both groups of fuel injectors whereby when the intake air flow rate Q is more than a predetermined value Q.sub.o, the fuel injectors of both groups are simultaneously opened to inject the fuel during an interval determined by T.sub.i =1/2.times.T.sub.p .times.COEF in synchronism with one half of engine rotation; when Q is less than Q.sub.o, the fuel injectors of either group are alternatingly opened to inject the fuel during an interval determined by T.sub.i =T.sub.p .times.COEF.times.(.alpha..sub.L or .alpha..sub.R).