Fuel System—Fuel pump & Fuel Filter

Fuel Pump

The fuel pump is installed in the fuel tank. From the outside, we can see two fuel pipes and a fuel pump connector are connected to it.

When the fuel pump is working, the PM motor is energized to drive the pump body to rotate, and the fuel is sucked from the fuel inlet. The speed of the fuel pump and the amount of oil pumped are determined by the applied voltage, which is usually a constant value. 

Here listed some common faults on fuel pumps

1. The safety valve leaks oil or the spring fails. Itmanifested in that the engine does not work smoothly or does not work, and the engine accelerates poorly.
2. The one-way valve leaks oil. Due to this, the engine is difficult to start.
3. The oil inlet filter is blocked. The fault is manifested as high-speed surge of the engine, poor acceleration, and unstable idling in severe cases.
4. The motor is burnt out, which causes the engine not working.
5. The fuel pump is worn. It will also result inhard tostart the engine, insufficient power, and poor acceleration.

Generally, the fuel pump couldn’t be repaired. When the above faults occur, the fuel pump assembly needs to be replaced.

Fuel Filter

The fuel filter is generally installed on the outlet pipe of the fuel pump, some beside the fuel tank, some under the rear seat, and some inside the fuel tank.

The function of the fuel filter is to remove solid impurities such as dust and rust in the fuel. When the fuel with impurities passes through the fuel filter, the impurities are adsorbed on the filter paper, and then filtered fuel flows to the engine.This prevents blockage of the oil supply system, reduces mechanical wear and improves the reliability of engine.

Blockage is the common fault of a fuel filter, which will lead to weak acceleration and lag in acceleration. To check it, remove the fuel filter. If the fuel poured out is cloudy, the fuel filter is clogged.