1, the concept of
EFI means automobile engine is normally provided by injection passage, and an electronic control unit sensor group composed of three parts. 
Multi-point EFI If the injector is mounted in the carburetor original position, i.e. the whole fuel injection engine is only a point, this is a single point fuel injection; if the injection of each cylinder is mounted in the the intake pipe, i.e., gasoline is injected by a plurality of places (for each cylinder has at least one injection point) spray people cylinder, which is multi-point fuel injection.
2, parts Application
If the injector is mounted in the carburetor original position, i.e. the whole fuel injection engine is only a point, this is a single point fuel injection; if the injection of each cylinder is mounted in the the intake pipe, i.e., gasoline is injected by a plurality of places (for each cylinder has at least one injection point) spray people cylinder, which is multi-point fuel injection.
3, single-point fuel injection (SPI) and the multi-point fuel injection (MPI) comparing
single-point fuel injection (SPI) and the multi-point fuel injection (MPI) comparing: a single point of electrical is computer controlled spray fuel into the intake manifold, and then successively taken into the combustion cylinders, an engine has only one nozzle; EFI is a multi-point fuel directly into each cylinder of the intake manifold, and then into the corresponding combustion, a nozzle for each cylinder. Multi-point EFI EFI engine is a mature technology development results, is currently the mainstream products. Since each is directly injected into each cylinder combustion air-fuel ratio control more accurate and therefore, better emissions, fuel economy and more. EFI is a single point of carburetor technology transition to EFI result, the carburetor works basically the same, so do not change the original carburetor engine block design directly to the carburetor change a computer-controlled equipment that is can. EFI is a multi-point injection with respect to a single point in terms! —— single point of injection throttle body provided in an intake manifold injector for each cylinder injection concentrated embodiments, gasolineIs sprayed into the intake air stream, to form a combustible mixer, assigned by the air intake manifold into the concept of multi-point injection —— respective cylinders are provided one per cylinder intake front injector, the implementation of each cylinder oil respectively. Multi-point injection control accuracy due to the reasons for higher is widely used. Most models are now almost multi-point EFI. Beverly three engines (1.4 / 8v, 1.6 / 8v and 1.6 / 16v) are multi-point fuel injection engine.
4, other explanations
EFI device
by the automobile engine is generally injection passage, and an electronic control unit sensor group composed of three parts. If the injector is mounted on each cylinder of the intake pipe, i.e., gasoline is injected by a plurality of places; if the injector is mounted in the carburetor original position, i.e. the whole fuel injection engine is only a point, this is a single point EFI (each cylinder has at least one injection point) spray people cylinder, which is multi-point fuel injection.