Here's a general outline. This is not a comprehensive guide, and variations may exist depending on your specific engine and trim level. Consult a repair manual specific to your 2003 Pontiac Sunfire for detailed instructions and diagrams. Improperly following these steps could lead to injury or damage to your vehicle.
1. Preparation:
* Safety First: Disconnect the negative battery terminal. Allow several minutes for any residual electricity to dissipate.
* Gather Tools: You'll need jack stands, jack, socket set (various sizes), wrenches, fuel line disconnect tool, pliers, screwdrivers (Phillips and flathead), possibly a fuel pump pliers, and a new fuel pump assembly.
* Refer to a Repair Manual: A Haynes or Chilton manual specific to your year and model Sunfire will provide detailed instructions and torque specifications.
2. Accessing the Fuel Pump:
* Locate the Fuel Pump Access Panel: This is usually located in the trunk, under the rear seat, or under the carpet in the rear passenger compartment. You may need to remove trim panels to access it.
* Drop the Fuel Tank (Possibly): On some Sunfires, you might only need to remove the access panel. On others, you might need to lower or even completely drop the fuel tank. This usually involves disconnecting the fuel lines, electrical connectors, and tank straps. Support the tank carefully to prevent damage. Be extremely cautious when working around the fuel tank.
3. Fuel Pump Replacement:
* Disconnect Fuel Lines: Carefully use the fuel line disconnect tool to separate the fuel lines from the pump. Have rags ready to absorb any spilled fuel.
* Disconnect Electrical Connectors: Unplug the electrical connector(s) from the fuel pump.
* Remove the Fuel Pump Assembly: This often involves removing a retaining ring, a retaining clip, or bolts securing the pump assembly.
* Install the New Fuel Pump Assembly: Carefully install the new fuel pump assembly, ensuring all seals and gaskets are properly seated. Reverse the removal process.
* Reconnect Fuel Lines and Electrical Connectors: Carefully reconnect the fuel lines and electrical connectors. Double-check for secure connections.
* Raise Fuel Tank (If Necessary): If you lowered the fuel tank, carefully raise it back into its position.
* Reconnect Battery: Reconnect the negative battery terminal.
4. Priming the Fuel System:
* Start the Engine: Try starting the engine. It may crank for a few seconds before it starts as the fuel pump primes. If it doesn't start, check your connections again.
Important Considerations:
* Fuel Pressure: Some vehicles require relieving fuel pressure before working on the fuel system. Consult your repair manual to see if this is necessary for your Sunfire.
* Fuel Smell: Even after disconnecting the battery, some fuel fumes might linger. Work in a well-ventilated area.
* Professional Help: If you're uncomfortable performing this repair yourself, take your Sunfire to a qualified mechanic.
This is a simplified overview. Always consult a repair manual specific to your 2003 Pontiac Sunfire for detailed, step-by-step instructions and safety precautions. Incorrectly performing this repair can be dangerous and may cause significant damage to your vehicle.
