The car fuel system is responsible for preparation and supply of fuel to the engine.
It is comprised of fuel pump, injector as well as the fuel tank, fuel filters and the eletric fuel control system. In order for the engine to work properly it is important to use good quality fuel.
Additionally, it is important for the balance between fuel and air to be just right. The balance is controled by the electic system.
Most common issues with the fuel system are issues with injectors and control of the balance between air and fuel.