Fuel injection control device for internal combustion engine

Abstract

A fuel injection control apparatus is provided with a fuel injection nozzle, a crank angle detector, a timer, and a control computer. The crank angle detector outputs a pulse signal corresponding to each tooth portion of a signal rotor and a pulse signal corresponding to a tooth missing portion. The control computer sets, as a fuel injection timing, a point of time at which a predetermined standby time period has elapsed from a point of time at which a reference tooth portion is detected. The control computer recognizes a tooth missing zone based on the pulse signal corresponding to the tooth missing portion. The control computer determines whether the fuel injection timing is set in a specific section in the tooth missing zone. When the fuel injection timing is set in a section outside the specific section, the control computer sets, as the predetermined standby time period, a remaining time period shorter than one inter-signal time period. In contrast, when the fuel injection timing is set to the specific section, the control computer sets, as the predetermined standby time period, a time period obtained by adding one or more inter-signal time periods to the remaining time period.