Fuel Pressure Regulator Control

This system is designed to improve hot engine startability by cutting off intake manifold vacuum and increasing fuel pressure. When coolant temperature is above a preset limit and engine speed is lower than 2500 RPM or with a light load, the ECU sends a signal to pressure regulator control solenoid valve. The electronic signal from the ECU energizes the coil inside of the pressure regulator control valve and pulls the plunger downward. This cuts off intake manifold vacuum and the positive pressure produced by pump is sent to the pressure regulator, therefore increasing fuel pressure. On some models, the fuel line is supplied with high pressure which is stored in a surge tank.