Why do cars need to clean fuel injectors? What are the benefits of cleaning them?

Modern engines are all EFI engines. Divided into manifold injection and in-cylinder direct injection.

In the manifold injection system, gasoline is sprayed through the fuel nozzle and then mixed with the air flow to form a mixture.

In the in-cylinder direct injection system, the injector injects gasoline directly into the cylinder.

No matter which injection method, in order to make gasoline and air fully mixed, it is required that the atomization ability of the oil nozzle is good. Like the sprayer at home, the state of gasoline sprayed must be very fine particles.

If the nozzle is not cleaned after long-term use, there will be carbon deposition around the nozzle hole, which will even block the nozzle seriously. The atomization state of fuel injection is not ideal, and gasoline and air can not be mixed well. Eventually, the engine may fail to burn sufficiently.