Fuel Injector: Description and Operation

FUEL INJECTORS AND RETURN LINES







A fuel injector is a solenoid device, controlled by the fuel injection control module (FICM), that meters pressurized fuel to a single engine cylinder. The engine control module (ECM) energizes the low-impedance injector solenoid to open a normally closed valve. Fuel pressure is released from above the fuel injector pintle, and is returned to the fuel tank through the fuel return lines. The difference in fuel pressure above and below the pintle causes the pintle to open. Fuel from the fuel injector tip is sprayed directly into the combustion chamber on the compression stroke of the engine.