High pressure fuel is supplied by an electric pump
in the fuel tank. Pressure is regulated by the
pressure regulator
. The fuel injector is a solenoid
operated device, controlled by the Powertrain
Control Module (PCM), that meters pressurized
fuel to a single engine cylinder. The PCM
energizes the high-impedance (12.0 ohms) injector
solenoid to open a normally closed ball valve. This
allows fuel to flow into the top of the injector, past
the ball valve, and through a director plate at the
injector outlet.

The director plate has four machined holes that
control the fuel flow, generating a spray of finely
atomized fuel at the injector tip. Fuel from the
injector tip is directed at the intake valve, causing
the fuel to become further atomized and vaporized
before entering the combustion chamber. An
injector stuck partly open can cause a loss of
pressure after engine shutdown. Consequently,
long cranking times would be noticed on some
engines. A leaking fuel pressure regulator can also
cause this.
Fuel Injector Operation And Decription

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