Electronic Fuel Injection

Electronic Fuel Injection (EFI) system is an electronically controlled system operated by incoming airflow. The EFI system also contains a feedback system which measures oxygen content of exhaust gases and maintains the air/fuel ratio near 14.7:1. The EFI system consists of 3 sub-systems: air intake system, fuel system and computerized system (ECA).

Each cylinder has a solenoid-operated injector which sprays fuel toward back of each intake valve. Injector bodies consist of solenoid-actuated pintle and needle valve assembly. Injector flow orifice is fixed, and fuel pressure at injector tip is constant. Atomizing spray is obtained by shape of pintle.

The ECA controls fuel injectors to meter pulse width or time each injector is energized. Each injector receives battery voltage through ignition switch circuit. The ECA completes ground circuit to energize injector. The ECA receives inputs from engine sensors to compute fuel flow necessary to maintain proper air/fuel mixture throughout entire engine operational range.