Section 03-04A: Fuel Charging and Controls, 4.9L Engine
1996 Vehicles Equipped with 4.9L SFI Engines Workshop Manual
DESCRIPTION AND OPERATION
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 (6007)engine is monitored by mass airflow, 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.