Trooper LS V6-3.5L (1998)
Fuel Injector: Description and Operation
The sequential multiport fuel injection (SFI) fuel injector is a solenoid-operated device controlled by the PCM. The PCM energizes the solenoid,
which opens a valve to allow fuel delivery.
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.
