Fuel pressure regulation system

This invention relates generally to a fuel delivery system and more particularly to a fuel pressure regulation system for a marine engine. A fuel pressure regulation system for use in a fuel pump system in which atomizing air is injected into the fuel delivered to the injector. The system includes both an air rail and a fuel rail and is operable to maintain the fuel pressure within the system at a consistent pressure above the air rail pressure. The system also includes a first pressure sensor, a second pressure sensor, a control circuit, and a fuel pressure pump or other fuel control device. The first and second pressure sensors are differential pressure sensors which measure the air and fuel pressure, respectively, convert those measurements into first and second electronic signals, and send those signals to the control circuit. The control circuit is an electronic circuit that includes a first stage, a second stage, and an output stage and provides the fuel pump with closed loop control based on the first and second signals. Preferably, the closed loop control is achieved using both proportional and integral control with the output being in the form of a pulse-width modulated signal. The fuel pump is in fluid communication with the fuel rail and adjusts the fluid pressure within the fuel rail according to the pulse-width insulated signal sent by the control circuit.