Fuel Injector

The Sequential Multiport Fuel Injection (SFI) fuel injector is a solenoid (3) operated device controlled by the PCM. The PCM energizes the solenoid which opens a valve (1) to allow fuel delivery onto the director plate (2).

The fuel is injected under pressure in a conical spray pattern at the opening of the intake valve. Excess fuel not used by the injectors passes through the fuel pressure regulator before being returned to the fuel tank.

A fuel injector which is stuck partly open will cause a loss of fuel pressure after engine shut down, causing long crank times to be noticed on some engines.