Before You Begin:
* Disconnect the negative battery terminal. This is crucial to prevent sparks and electrical hazards.
* Consult a repair manual specific to your 1991 Oldsmobile Ninety-Eight. This manual will provide detailed diagrams, torque specifications, and crucial step-by-step instructions tailored to your vehicle. Haynes and Chilton manuals are readily available.
* Gather your tools. You'll likely need:
* Socket set (various sizes)
* Wrenches (various sizes)
* Screwdrivers (Phillips and flathead)
* Fuel pump pliers or a fuel line disconnect tool
* Jack and jack stands (essential for safety)
* Wheel chocks
* Safety glasses
* Gloves
* Rags
* Container to catch fuel
* New fuel pump and filter (ensure they're the correct ones for your car)
* Possibly a fuel pressure gauge (to check pressure after installation)
General Steps (Consult your repair manual for specific details):
1. Prepare the Vehicle: Securely jack up the rear of the car and place it on jack stands. Chock the front wheels.
2. Access the Fuel Pump: This typically involves removing parts of the undercarriage or accessing it through a panel in the trunk (depending on your Ninety-Eight's configuration). Your repair manual will show you exactly where the fuel pump assembly is located and the necessary steps to access it. This often involves removing the access panel (if applicable) and potentially the fuel tank skid plate.
3. Disconnect the Fuel Lines: Carefully disconnect the fuel lines leading to and from the fuel pump. Use fuel line disconnect tools to avoid damaging the lines. Have your container ready to catch any residual fuel. Be extremely careful not to ignite any spilled fuel.
4. Disconnect the Electrical Connectors: Unplug the electrical connector(s) from the fuel pump.
5. Remove the Fuel Pump Assembly: The pump is usually held in place by a retaining ring or a series of bolts. Remove these fasteners carefully. You may need to remove the fuel pump access plate. The entire assembly may be removed as a unit, or the pump may need to be separated from the assembly.
6. Install the New Fuel Pump: Carefully install the new fuel pump and any related gaskets or seals as per your repair manual.
7. Reconnect Everything: Carefully reconnect the electrical connectors, fuel lines, and secure the fuel pump assembly.
8. Lower the Vehicle: Carefully lower the vehicle from the jack stands.
9. Prime the Fuel System (Important!): After reconnecting everything, you may need to prime the fuel system. This usually involves turning the ignition key to the "ON" position several times (without starting the engine) to allow the pump to fill the fuel lines. Your repair manual will outline the proper priming procedure.
10. Check for Leaks: Carefully inspect all connections for leaks.
11. Start the Engine: Once you are confident everything is connected correctly, start the engine and listen for any unusual noises. Check for fuel leaks.
12. Test Drive: Take a short test drive to ensure the fuel pump is working correctly.
Important Considerations:
* Fuel Pressure: After replacing the fuel pump, consider using a fuel pressure gauge to check the fuel pressure. This ensures the pump is operating within the correct specifications.
* Professional Help: If you're uncomfortable performing this repair yourself, it's best to take your vehicle to a qualified mechanic. Working with fuel systems is dangerous, and a mistake could be costly.
This is a general outline. Always refer to a repair manual specific to your 1991 Oldsmobile Ninety-Eight for detailed instructions and diagrams. Improper repair could lead to vehicle damage or serious injury.
