Electronic Engine Controls

The fuel pressure sensor senses the pressure difference between the fuel injection supply manifold and the intake manifold, and provides the PCM with the current fuel injection supply manifold pressure. The return fuel line to the fuel tank has been deleted in this type of fuel system.

The PCM uses this information to vary the duty cycle output to the Fuel Pump Driver Module (FPDM) which controls the speed of the fuel pump. The speed of the fuel pump sustains fuel injection supply manifold pressure which preserves fuel in its liquid state.

The dynamic range of the fuel injector's increase is due to the higher pressure, which allows the injector pulse width to decrease.