Fuel Injection Timing

For 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 is monitored by mass air flow, pressure and temperature sensors.
• The outputs of the 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 injectors to meter the exact quantity of fuel.