Fuel Pressure Regulator (PRVR) Control System

FUEL PRESSURE REGULATOR CONTROL







SYSTEM DESCRIPTION
The fuel "pressure-up" control system briefly increases fuel pressure for improved starting performance of a hot engine. Under normal operating conditions, manifold vacuum is applied to the fuel pressure regulator. When starting the engine, however, the ECM allows current to flow through the ON/OFF solenoid valve in the control vacuum line, opening this line to the atmosphere. As a result, atmospheric pressure is applied, restricting the fuel return line so as to increase fuel pressure.




COMPONENT DESCRIPTION
Fuel Pressure Regulator Control Solenoid Valve
The solenoid valve responds to the ON/OFF signal from the ECM. When it is off, a vacuum signal from the intake manifold is fed into the fuel pressure regulator. When the ECM sends an ON signal, the coil pulls the plunger downward and cuts the vacuum signal.




Fuel Pressure Regulator
The fuel pressure regulator maintains the fuel pressure at 299.1 kPa (3.05 kg/cm2, 43.4 psi). Since the injected fuel amount depends on injection pulse duration, it is necessary to maintain the pressure at the above value.




WIRING DIAGRAM







DIAGNOSTIC PROCEDURE

COMPONENT INSPECTION
Fuel Pressure Regulator Control Solenoid Valve




Check air passage continuity.




If NG, replace solenoid valve.