New Original Pressure Regulator Suction Pressure Valve 0 281 002 494 SCV Valve for Auto Spare Parts 0281002494

The oil pump SCV valve, or suction control valve, is a key component in the diesel engine fuel system. The following is a detailed introduction:

Function: It is mainly used to control the flow and pressure of fuel entering the high-pressure oil pump, thereby adjusting the engine speed and power. It forms a closed-loop control of the rail pressure with the rail pressure sensor to ensure that the common rail system reaches the set pressure, which is crucial to the fuel efficiency and operating stability of the engine.

Working principle: The SCV valve is usually an inverse proportional electromagnetic proportional valve controlled by the ECU. The ECU receives signals such as engine speed, water temperature, and common rail pressure, and sends a command current to the SCV valve to control the valve opening. When the solenoid valve is energized, the electromagnetic force attracts the needle valve to overcome the spring force and lift it upward, and the fuel enters the pump unit through the SCV; after the power is off, the needle valve closes the fuel channel under the action of the spring force. By controlling the length of the power-on time, the needle valve lift amount can be adjusted, thereby controlling the fuel channel opening and the amount of oil suction.

Structural type: SCV valves are of two types: normally open and normally closed. The normally open oil suction valve opens when the power is off, and the fuel channel is unobstructed; the normally closed type is the opposite, and the fuel channel is closed when the power is off.
Installation location: Generally integrated on the high-pressure oil pump, it is the only way for the fuel in the tank to enter the high-pressure pump.

Common faults: including valve core stuck, coil breakage, electromagnet failure, magnetic core damage, oil inlet and outlet blockage, etc., which may cause problems such as engine power reduction, inability to start or sudden flameout.