Here's a general outline of the steps involved. Again, this is not a substitute for a proper repair manual.
1. Safety First:
* Disconnect the battery negative terminal. This prevents accidental sparks that could ignite fuel vapors.
* Work in a well-ventilated area. Fuel vapors are highly flammable.
* Wear safety glasses and gloves.
* Have a fire extinguisher nearby.
2. Preparation:
* Locate the fuel pump access panel. This is usually located under the rear seat, in the trunk, or under the car near the fuel tank. Consult your repair manual for the exact location. You might need to remove the rear seat cushion or other interior panels.
* Gather necessary tools. You'll likely need various sockets, wrenches, screwdrivers (possibly including Torx bits), pliers, and possibly a fuel pump removal tool. A fuel line disconnect tool is highly recommended.
* Obtain a new fuel pump and fuel filter. Always replace the fuel filter at the same time. Ensure the new pump is the correct one for your Malibu's engine.
3. Fuel System Depressurization:
* Start the engine and let it run until it stalls. This depletes the fuel pressure in the system.
* Wait several minutes to allow any remaining pressure to dissipate.
4. Accessing the Fuel Pump:
* Remove the fuel pump access panel. This may involve removing bolts, clips, or other fasteners.
* Disconnect the electrical connector to the fuel pump.
* Disconnect the fuel lines. This is crucial and potentially messy. Use a fuel line disconnect tool to prevent damage and leakage. Have rags or absorbent material ready to soak up any spilled fuel.
* Remove the retaining ring or bolts holding the fuel pump assembly in place. This will likely involve removing a fuel pump retaining ring or clamp.
5. Fuel Pump Removal and Replacement:
* Carefully remove the fuel pump assembly. The pump is usually attached to a sending unit. Take note of the orientation and position of all components before removing.
* Compare the old pump to the new one. Ensure all components match and are installed correctly.
* Install the new fuel pump assembly. Make sure to align it properly and secure it with the retaining ring or bolts.
* Reconnect the fuel lines, ensuring tight connections. Use clamps if necessary.
* Reconnect the electrical connector.
6. Reassembly and Testing:
* Reinstall the fuel pump access panel.
* Reconnect the battery negative terminal.
* Start the vehicle and check for leaks. Inspect the fuel lines and connections for leaks.
* Let the engine run for a few minutes to ensure the pump is working correctly.
* Check for any fuel odors or leaks.
Important Considerations:
* Fuel pressure: Some fuel pumps require priming after installation. Your repair manual should provide information on this.
* Fuel filter: As mentioned, replace the fuel filter.
* Fuel pump relay: If you suspect a relay problem (and not the pump itself), testing and replacing the relay is much simpler and cheaper.
This is a simplified overview. Consult a repair manual specific to your 1999 Chevrolet Malibu for detailed instructions, torque specifications, and diagrams. If you are not comfortable performing this repair, it's best to take your vehicle to a qualified mechanic. Working with fuel systems is inherently dangerous if not done correctly.
