Mercedes-Benz A6420740284 Fuel Pressure Regulator Valve

The A6420740284 is a fuel pressure regulator valve designed for Mercedes-Benz common rail diesel injection systems. It regulates fuel pressure within the high-pressure circuit by controlling the fuel quantity delivered to the rail, ensuring optimal air-fuel mixture across engine operating conditions. The valve is mounted on the high-pressure pump or fuel rail assembly and operates via PWM signal from the ECU. It is a critical component for maintaining injection pressure stability, reducing emissions, and improving fuel economy. Failure symptoms include rough idle, power loss, hard starting, and fault codes related to fuel pressure deviation. This component is manufactured to OEM specifications by Bosch (0928400719, 1465ZS0087) and supplied as genuine Mercedes-Benz equipment.