Fuel System

 WARNING: DO NOT SMOKE, CARRY LIGHTED TOBACCO, OR OPEN FLAME OF ANY TYPE WHEN WORKING ON OR NEAR ANY FUEL-RELATED COMPONENT. HIGHLY FLAMMABLE MIXTURES ARE ALWAYS PRESENT AND MAY BE IGNITED, RESULTING IN POSSIBLE PERSONAL INJURY.

The sequential multiport fuel injection (SFI) system is classified as:

• Multi-point.
• Pulse time.
• Mass air flow controlled.

Fuel is metered into each intake port in sequence with the engine firing order in accordance with engine demand through fuel injectors (9F593) mounted on a tuned intake manifold (9424) .

The on-board powertrain control module (PCM) (12A650) :

• Accepts inputs from various engine sensors to compute the required fuel flow rate necessary to maintain a prescribed air/fuel ratio throughout the entire engine operational range.
• Outputs a command to the fuel injectors to meter the appropriate quantity of fuel.
• Determines and compensates for the age of the vehicle and its uniqueness.
• Automatically senses and compensates for changes in altitude (i.e. from sea level to mountains).
• Permits push-starting the vehicle should it become necessary (manual transmission only).

The "Unleaded Fuel Only" nomenclature must appear:

• Near the fuel filler opening.
• On the instrument cluster.

The fuel delivery sub-system delivers fuel to the fuel charging system and consists of the following:

• High-pressure, in-tank mounted fuel pump (9350) fuel filter/reservoir in the fuel tank (9002) .
• 20 micron fuel filter (9155) .
• Fuel supply and return hoses.

The fuel charging system incorporates a fuel injection supply manifold (9F792) with electrically actuated fuel injectors directly above each of the engine's intake ports. The fuel injectors , when energized, spray a metered quantity of fuel into the intake air stream.

A constant fuel pressure drop is maintained across the fuel injectors by a fuel pressure regulator (9C968) . The fuel pressure regulator is:

• Connected in series with the fuel injectors .
• Positioned downstream from the fuel injectors .

Excess fuel supplied by the fuel pump , but not required by the engine, passes through the fuel pressure regulator and returns to the fuel tank through a fuel return line.