Fuel Injectors
Fuel injector nozzles are solenoid operated valves which both meter and atomize fuel delivered to engine. Injectors are mounted in lower intake manifold with their nozzles injecting fuel just upstream of engine intake valves.
Injector bodies consist of solenoid actuated pintle and needle valve assembly. Electrical control signal from ECA unit activates injector solenoid, causing pintle to move inward off seat, allowing fuel to flow.
Since 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.