High-pressure pump BOSCH, Common Rail system

The fuel metering proportional valve is installed at the fuel inlet position of the high-pressure fuel pump and is used to adjust the fuel supply volume and fuel pressure value. And its adjustment requirements are controlled by ECU. When the fuel metering proportional valve is not energized, the fuel metering proportional valve is on and can provide the maximum flow of fuel.

The role of the automobile metering unit is to control the oil intake and return flow of the high-pressure oil pump, thereby controlling the oil supply of the oil pump plunger to the rail, meeting the set pressure of the common rail system, and forming a closed loop control of the rail pressure with the rail pressure sensor. The internal structure of the fuel metering unit is not complicated. It consists of three parts: a housing with an electromagnetic coil, an upper cover with an oil hole, and a valve core that can move up and down. When it is damaged, just replace it with a new one.

The fault code is P1014,The flow rate in the fuel pressure relief valve exceeds the threshold value during reverse driving; The fault code is P0504,The signals of the brake main and auxiliary switches are not credible; P2299: The throttle and brake signals are not credible.

Once the electronically controlled engine fails, the fuel injector and fuel metering unit will be replaced frequently. Among them, the suction control valve is often due to the valve body being worn and stuck, which often leads to failures such as difficulty in establishing rail pressure, difficulty in starting, intermittent flameout, and speed limit at 1500 rpm.

In terms of machinery, if the oil system is not tightly sealed, it will be difficult to ignite if the air enters, or there will be flameout or vehicle movement when the middle of the fuel line is not clear. In terms of electricity, if the sensor is damaged, the engine will be weak, and it will be difficult to stop and start; if you can’t refuel, just look at the accelerator pedal; when welding, you must disconnect the computer version plug, and usually pay attention to maintenance to avoid the computer version. Corrosion of electronic components.

The working principle of the fuel metering unitSo what exactly does the fuel metering unit do? The fuel metering unit is also called the fuel metering proportional valve. It is installed in the fuel inlet position of the high-pressure fuel pump, used to adjust the fuel supply and fuel pressure value.

The suction control valve (fuel inlet metering valve) is one of the most important components in the diesel engine fuel supply system, and it is the most important part of the throat.

When your car has stalling issues, bad rough idling, huge RPM fluctuation problems, you have to consider that it may be the suction control valve(SCV) problem! The suction control valve is often overlooked when you are having issues with your vehicle.