The engine ECU changes the fuel injection volume by changing the injector injection duration. The actual fuel injection duration is determined by the following two items.
1. The basic injection duration is determined by the amount of the intake air and the engine speed.
2. The various corrective injection durations are determined by the signals from the various sensors. The injection duration that the engine ECU finally outputs into the injector is added various corrections to the basic injection duration. There are following corrections:
Start enrichment
Warm-up enrichment
Air-fuel ratio feedback correction (some models only)
Acceleration enrichment
Fuel cut-off
Power enrichment
Other corrections