F 450 4WD Super Duty V8-6.0L DSL Turbo VIN P (2003)
To drive the fuel injector the FICM produces two control signals for each injector.
The open coil is driven (via a 20A pulse) to open the injector. This shifts the spool valve in the injector to the open state. Once this has taken place, high
pressure oil is directed on top of the injector intensifier piston. In result, fuel is being delivered through the nozzle of the injector.
Once the desired fuel has a been delivered, as calculated by the PCM/FICM, the close coil is driven (via a 20A pulse) to close the injector. This stops the
distribution of high pressure oil to the top of the intensifier piston thus stopping the delivery of fuel.
The net time between pulses is equivalent to the fuel pulse width (FuelPW) used to provide fueling.
The coil on time is currently calibrated from 400us to 5.8ms. The 5.8ms is for cold starts. As the engine warms up the duration decreases and settles
around 800us depending on the amount of fuel being commanded.
