As one of the "three filters" in maintenance projects, fuel filters are generally arranged in major maintenance. Once the fuel filter is blocked, it will cause insufficient oil supply, which will lead to too thin mixture, weak acceleration, car bumps and car slapping.

Second, the fuel pump failure

If the fuel pump fails, even if the filter screen of the fuel pump is blocked, the fuel supply pressure will be insufficient and the mixture will be too thin.

Third, the air flow sensor is faulty.

The air flow sensor, like the oxygen sensor, can be called the "senior staff" of the engine head ECU. Once the air flow sensor fails, the ECU can't get the correct intake signal, which will lead to a series of faults such as unbalanced mixture concentration, unstable idle speed, weak acceleration, black smoke from the exhaust pipe, and ignition. Even the exhaust gas exceeds the standard like the failure of the oxygen sensor.

Fourth, the nozzle is blocked.

Nozzle blockage is mostly caused by impurities, colloid compounds and carbon deposits in oil, and nozzle cleaning is also a maintenance project, because once the nozzle is blocked, the concentration of mixed gas will be too dilute.

Five, water temperature sensor failure

The fault of water temperature sensor will send an error signal to ECU, resulting in unbalanced concentration of mixed gas. Generally, the failure of water temperature sensor can easily lead to the high concentration of mixed gas, and the failure phenomenon of exhaust shooting and black smoke appears.