Protege L4-1839cc 1.8L DOHC (1990)
Fuel Injector: Description and Operation
Typical Fuel Injector
The fuel injectors, located on the intake manifold near the cylinder head, are electrically operated, high impedance solenoid valves that open when
energized. The injectors get battery power from the main relay when the ignition is in the either the "START" or "RUN" position, and are energized
when the ECU completes the circuit to ground. Injection timing and duration is determined by the engine control unit. Injectors are energized either all at
the same time once each crankshaft revolution (during cranking and cold engine operation), or in pairs (normal warm engine operation).
The injectors are constructed of stainless steel and high density plastic, to resist corrosion. They consist of a fuel inlet with filter screen, an electrical
solenoid and connector, and a pintle valve and nozzle. Injectors are held in place by the fuel rail and sealed by an O-ring and insulator.
