Choosing the right fuel injector depends on the kind of fuel injector used in your vehicle. The common kinds of fuel injectors are:
Single-Point or Throttle Body Injection (TBI) Systems:
The throttle body injection systems were the first to replace the carburetors. The throttle body system included one or two fuel injectors in place of the carburetors. The fuel injectors were controlled by an on-board computer and provided better fuel economy than the carburetors.
Multi-Point or Port Fuel Injection (MPFI) Systems:
The multi-point fuel injection system included one fuel injector in each engine intake port of the manifold. Therefore, instead of dumping the fuel into a single place before passing it to the various cylinders, the MPFI system delivers fuel into the intake ports at the same time.
Sequential Fuel Injection (SFI) Systems:
The sequential fuel injection systems are similar to the multi-point fuel injection systems except that the fuel injection is controlled in a more efficient way. Instead of firing the injectors at the same time, the fuel is injected into the intake port just before the intake valve is opened for each cylinder.
Direct Fuel Injection Systems:
This fuel injection mechanism injects the fuel directly into the combustion chamber, rather than injecting it into the intake valves. This prevents the fuel from being wasted in the form of carbon deposits in the intake valves. Direct fuel injection is common in diesel engines but has recently been introduced in gasoline engines, as well.