Closed-Loop Electronic Fuel and Air Control of Internal Combustion Engines

Utilizing a closed loop EFI system with an oxygen (Lambda) sensor as a feedback element, techniques are demonstrated to expand the A/F operating range up to 10% from a stoichiometric calibration.

Fuel injection timing techniques, such as “simultaneous double fire,” are presented which further enhance the transient engine response of EFI vehicles.

A closed loop air control system operating with the EFI system is discussed. This system has resulted in improved idle-speed control during both cold-and warm-engine operating conditions.