Fuel Injection Timing

Each fuel injector (9F593) is energized once every other crankshaft revolution in sequence with engine firing order. The period of time that the fuel injectors are energized (injector "on time" or pulse width) is controlled by the vehicle's powertrain control module (PCM) (12A650). Air entering the engine (6007) is monitored by flow, pressure and temperature sensors. The outputs of these electronic engine control sensors are processed by the powertrain control module. The powertrain control module determines the needed fuel injector pulse width and outputs a command to the fuel injector to meter the exact quantity of fuel.