Fuel Injectors

A fuel rail links the fuel pressure regulator with fuel injectors. Each cylinder is provided with a solenoid operated injector, mounted to directly spray fuel towards back of each inlet valve. Each injector is energized through the distributor (coil) and grounded through the ECU to complete the electrical circuit. Each injector is linked in series to a resistor (except TR7 and all Fiat models) which reduces operating voltage of the injector and also protects injector from power surges. The ECU controls the electrical pulsations required to open each injector and the length of time each injector is open. Therefore, no fixed relationship exists between injector timing and ignition timing or valve timing. The time that the injectors are open governs the amount of fuel delivered and the time is controlled by interpretation of sensor impulses received by the ECU. Each injector opens at the same time to deliver 1/2 the fuel required for ideal combustion with each engine revolution.