The main difference between single point and multi-point fuel injection systems is that the single point fuel injection system uses a single fuel injector for the mixing of fuel with air while the multi-point fuel injection system has a separate fuel injector for each cylinder of the engine.
Single point fuel injection system:
Single point fuel injection system is a fuel injection system that uses a single fuel injector for the mixing of fuel. In this system, the fuel is mixed with air before it reaches to the intake manifold.
It is also known as the throttle body fuel injection system.
Multi-point fuel injection system:
Multi-point fuel injection is the type of fuel injection system that uses a separate fuel injector for each cylinder.
The injector sprays the fuel in the intake manifold above the intake valve of each cylinder.
This fuel injection system is considered as more efficient than the single-point fuel injection system.
Single point vs Multi-point fuel injection system:
|Single-point fuel injection system
|Multi-point fuel injection system
|It uses only a single injector for fuel injection.
|It uses a separate fuel injector for each cylinder.
|The fuel is injected before the intake manifold.
|The fuel is injected into the intake manifold before the intake valve.
|It is arranged before the throttling body.
|It is provided after the throttling body.
|It is also known as throttle body injection.
|It is also known as a port fuel injection system.
|The air-fuel ratio is not uniform for all the cylinders.
|The air-fuel ratio is more uniform than single-point fuel injection.