What causes the fuel pressure to be too low or the holding pressure to be abnormal?

Causes of low fuel pressure in EFI engines:

If the oil pressure of the EFI car is too low, it is easy to cause unstable idling, the engine is shaking, and the road driving power is insufficient.

First, the fuel pump is relieved, and the reason is that the oil pressure is discharged quickly, and the accumulator is not good;

The second is that the fuel pressure adjustment is damaged, which can maintain the oil pressure for a while;

The third is that the injector is not well sealed, the pressure relief is slow, and the short-term shutdown does not affect the start.

When the engine is working, the gasoline pump works, and the fuel in the fuel tank is pumped into the oil supply system, and the oil pressure of the oil supply system is regulated by the oil pressure regulator, which is generally controlled at about 300kpa higher than the pressure of the inlet pipe. The path through which the fuel injected into the engine cylinder flows: gasoline tank - gasoline pump - fuel delivery pipe - gasoline filter - fuel distribution pipe - injector.

The injector injects fuel near the intake valve. When the engine is working and the intake valve is open, the cylinder is sucked in for combustion. When the fuel of the gasoline pump pump fuel supply system increases, and the oil pressure in the oil circuit increases, the oil pressure regulator will automatically adjust the fuel system pressure.

Ensure that the oil pressure supplied to the injector is basically unchanged. Excess fuel from the supply system flows back to the tank through the return pipe.

The electric gasoline pump pumps the gasoline out of the fuel tank, first filters through the gasoline filter, and then adjusts the oil pressure through the oil pressure regulator, so that the oil pressure in the oil circuit is about 300kpa higher than the negative pressure of the intake pipe, and finally distributes to the fuel injector of each cylinder through the fuel distribution pipe, and the fuel injector sprays the gasoline near the throttle valve in time according to the instructions of the electronic control unit ECU.

To install the oil pressure gauge, first depressurize the fuel system, start the engine, and unplug the electric gasoline pump relay or power supply. After the engine is turned off, start the engine 2-3 times again to release the fuel pressure.

The oil pump is depressurized, and the injector is leaking. Tubing rupture.

It is recommended that you check the above places to make sure there are no leaks. Thank you.

cause analysis; The fuel regulator is damaged, the fuel mercury supply is insufficient, the fuel mercury inlet filter is blocked, and the oil pipeline is damaged

The low fuel pressure could be due to a problem with the oil pump or a problem with the gasoline filter. A gasoline filter is a component that needs to be replaced regularly, and this filter can filter out moisture and impurities in gasoline.

If it is not replaced regularly, it will lead to problems with the fuel supply of the car.

The gasoline pump is inside the fuel tank and is responsible for pumping the gasoline out and supplying it to the engine.

If the gasoline pump is broken, that will cause the gasoline pressure to be too low.

There are many engines with direct in-cylinder injection, which also has a high-pressure oil pump in the engine compartment.

The gasoline injection pressure in the direct injection engine is very high, so a separate high-pressure oil pump is required.

If the high-pressure oil pump is broken, that will also cause the gasoline pressure to be too low.

If this happens, it is recommended that riders check the high-pressure oil pump and the source round gasoline pump, and check whether the gasoline filter is still working properly.

If you use low-quality gasoline for a long pre-grinding time, it will lead to increased carbon deposits in the engine, which will lead to knocking phenomena in the engine during operation.

Knocking causes engine power to decrease, fuel consumption to increase, and knocking can also damage the engine.

When you use your car, you must maintain your car on time.

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