Fuel Injector: Description and Operation

Fuel Injector:

DESCRIPTION
The Sequential Fuel Injection (SFI) fuel injector is a solenoid operated device controlled by the Powertrain Control Module (PCM). The PCM energizes the solenoid which opens a valve to allow fuel delivery.

OPERATION
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 pressure regulator before returning to the fuel tank. An injector which is stuck partly open will cause a loss of pressure after engine shutdown, causing long crank times to be noticed on some engines.