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 a sequential firing order. Fuel injector (9F593) pulse to follow ignition firing order in accordance with engine demand. Fuel injectors are mounted on the cylinder heads (6049) .

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

• Accepts inputs from various electronic engine sensors to compute the required fuel flow rate necessary to maintain a prescribed air/fuel ratio throughout the 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 sense and compensate for changes in altitude (i.e. from sea level to mountains).
• Permit 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 electric fuel pump (9350) .
• Fuel filter/reservoir delivering fuel from the fuel tank (9002) .
• 20-MICRON fuel filter (9155) .
• Fuel supply and return tubes.

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.