Fuel Injectors

On PFI engines, each cylinder has a solenoid-operated injector which sprays fuel toward back of each intake valve. On TBI engines, a single injector is mounted in the throttle body. On all fuel injected models, the ECA controls length of time each injector is on, or energized.

Fuel injector nozzles are solenoid operated valves which meter and atomize fuel delivered to engine. Each injector receives battery voltage through an ignition switch circuit. The ECA controlled ground circuit is used to complete the circuit and energize (on time) the injector. The on time governs the amount of fuel delivered.

Injector bodies consist of solenoid actuated pintle and needle valve assembly. Injector flow orifice is fixed and fuel pressure at injector tip is constant. Fuel flow to engine is regulated by how long solenoid is energized. This length of time is known as "pulse width". Atomization spray is obtained by shape of pintle.