Here's a general outline. Specific steps and locations may vary slightly depending on the exact engine (e.g., 1.8L, 2.0L, 2.5L V6) and whether it's a sedan, coupe, or wagon. Always consult a repair manual specific to your 1990 Cavalier's year, engine, and body style for precise instructions and diagrams.
Steps:
1. Safety First: Disconnect the negative battery cable.
2. Prepare the Vehicle: Jack up the car securely and support it on jack stands. Locate the fuel pump access panel. This is typically under the rear seat (for some models, it might be in the trunk).
3. Access the Fuel Pump:
* Remove the rear seat: This usually involves unclipping or removing bolts. Consult your repair manual.
* Locate the access panel: This panel covers the fuel pump assembly. It might have clips or bolts holding it in place. Remove it carefully.
4. Release Fuel Pressure: This is crucial to prevent fuel spraying. There are a couple of ways to do this:
* Method 1 (Safest): Use a fuel pressure relief tool. This tool is specifically designed to safely release pressure.
* Method 2 (Less Safe, Only if you have no tool): Start the car and let it run until it stalls due to fuel starvation. This method carries a higher risk of residual pressure.
5. Disconnect Electrical Connections: Carefully disconnect the electrical connectors from the fuel pump. Note the connections to ensure you can reconnect them correctly. Take pictures if you are unsure.
6. Disconnect Fuel Lines: There will be at least two fuel lines connected to the pump (supply and return). Use fuel line clamps to avoid spills and make reconnection easier. Place a rag or absorbent material under the lines to catch any drips.
7. Remove the Fuel Pump Assembly: This is usually held in place by a retaining ring or a bolt. Carefully remove the assembly. Some models have a fuel pump retaining ring that requires specialized tools for removal.
8. Inspect the Old Fuel Pump: Check the old fuel pump for any signs of damage that might indicate a contributing issue (e.g., debris in the fuel filter).
9. Install the New Fuel Pump: Carefully install the new fuel pump, ensuring it's seated correctly and the gasket is properly positioned.
10. Reconnect Everything: Reconnect the fuel lines securely using clamps, the electrical connector, and then reassemble the retaining ring or bolt. Tighten everything to the manufacturer's specifications.
11. Reinstall the Access Panel and Rear Seat: Replace the access panel and rear seat.
12. Reconnect the Battery: Reconnect the negative battery cable.
13. Prime the Fuel System: You might need to turn the ignition key to the "ON" position (without starting the car) for several seconds several times to allow the fuel pump to prime and fill the lines.
14. Test: Start the car and check for leaks around the fuel lines and connections. Let the car run for a while to ensure the new fuel pump is working correctly and there are no issues.
Important Notes:
* Repair Manual: A repair manual specific to your 1990 Cavalier is essential. It provides detailed instructions, diagrams, and torque specifications.
* Fuel Safety: Work in a well-ventilated area. Avoid sparks or flames.
* Fuel Pump Replacement Kit: Consider buying a fuel pump replacement kit that includes the fuel filter and any necessary gaskets or seals.
* Professional Help: If you're uncomfortable performing this repair yourself, it's best to take your car to a qualified mechanic. Improperly installed fuel pumps can be dangerous.
This is a general guide. Always refer to your vehicle's specific repair manual for detailed instructions. Improper installation can lead to serious problems, including fire. If you're uncertain about any step, seek professional assistance.
