What faults will occur if the high-pressure fuel pump loses pressure?

[DelPaige]

If the high-pressure fuel pump loses pressure, the engine may be difficult to start and may stall during startup. More details are as follows: 1. Pressure relief valve explanation: The pressure relief valve, also known as the overflow valve or safety valve, opens when the fuel supply line pressure exceeds the limit, directly releasing the pressure into the fuel tank. For example, the general limit is 450kpa. Possible causes include blockage or bending of the fuel supply line, bending or blockage of the return line, or a clogged fuel filter. 2. Inspection method: First, determine whether it is a fixed displacement pump or a variable displacement pump. For a fixed displacement pump, check the pump's maximum pressure. If it meets the standard, try replacing the overflow valve. If there is still no change, check whether the pump is severely worn or has excessive internal leakage. For a variable displacement pump, first check the pump's pressure setting, and then follow the same steps as for a fixed displacement pump.