Replacing The Fuel Pump In Your 1991 Buick Park Avenue

To replace the fuel pump on a 1991 Buick Park Avenue, first disconnect the negative battery cable and relieve the fuel system pressure. Next, raise the vehicle with jack stands and drain and remove the fuel tank assembly. Then, turn the fuel pump cam lock ring counterclockwise and lift the assembly out of the tank. Remove the fuel pump from the level sensor unit by pulling the pump up into the attaching hose or pulsator while pulling outward away from the bottom support. Take care to prevent damage to the rubber insulator and strainer during removal. When the pump assembly is clear of the bottom support, pull the pump out of the rubber connector for removal.

The fuel pump is located in the fuel tank

To replace the fuel pump on a 1991 Buick Park Avenue, you'll first need to locate the fuel pump, which is found in the fuel tank.

Step-by-Step Guide to Replacing the Fuel Pump:

Accessing the Fuel Pump:

Start by popping the trunk and removing the carpet. There is some discrepancy in the information found online regarding access to the fuel tank. Some sources state that there is an access door in the trunk, just above the fuel tank, while others claim that the fuel tank is located under the rear seat, in front of the rear axle, with no access from the trunk.

Disconnect the Battery:

Before proceeding any further, it is crucial to ensure your safety by disconnecting the negative battery cable.

Prepare for Fuel Pump Removal:

The next steps involve relieving the fuel system pressure, raising and safely supporting the vehicle with jack stands, and safely draining and removing the fuel tank assembly.

Remove the Fuel Pump:

Once you have accessed the fuel tank, you can begin the process of removing the fuel pump. Turn the fuel pump cam lock ring counterclockwise and lift the assembly out of the tank. Carefully pull the pump up and out, away from the bottom support, being cautious not to damage the rubber insulator and strainer.

Install the New Fuel Pump:

When installing the new fuel pump, push it into the attaching hoses and install the pump/sensor assembly into the tank. Always use a new O-ring seal. Ensure that the strainer does not block the full travel of the float arm, and be careful not to fold or twist the strainer. Install the cam lock and turn it clockwise to lock it into place.

Reassemble and Check for Leaks:

After installing the new fuel pump, reinstall the fuel tank as outlined in the vehicle's maintenance instructions. Pour 4 gallons of fuel into the tank and carefully check for any signs of fuel leaks.

Please note that this is a complex procedure, and it is always recommended to consult a certified mechanic or a professional repair shop if you are unsure about any steps or feel uncomfortable performing the replacement yourself.

Disconnect the negative battery cable

Disconnecting the negative battery cable is one of the first steps to take when replacing the fuel pump on a 1991 Buick Park Avenue. This is a crucial safety precaution as it ensures that there is no electrical current that could ignite the fuel.

To disconnect the negative battery cable, first locate the battery. It is usually located in the engine bay, on the side of the vehicle, or in the trunk. Once you have located the battery, look for the negative terminal. This will be clearly marked with a "-" symbol or a black cover. Using a wrench or socket, loosen the nut that secures the cable to the terminal. Do not allow the wrench or socket to touch any other metal parts of the car, as this could cause a short circuit. Once the nut is loose, carefully remove the cable from the terminal. Be sure to avoid touching any metal parts of the cable or terminal, as this could result in a dangerous electrical shock.

It is important to note that the battery should only be disconnected once the vehicle is securely raised and supported on jack stands. This will ensure that you have safe and easy access to the battery and fuel pump. Additionally, always refer to the owner's manual for specific instructions related to your vehicle.

After disconnecting the negative battery cable, the next step is to relieve the fuel system pressure. This is done by depressing the valve in the service port, which is located on the fuel injector rail. This will release any built-up pressure in the fuel lines, making it safe to work on the fuel pump.

Remove the fuel tank assembly

To remove the fuel tank assembly of a 1991 Buick Park Avenue, follow these steps:

Firstly, pop the trunk and remove the carpet. There is some disagreement over the location of the access door to the fuel tank. One source states that there is an access door just above the fuel tank, while another source states that the fuel tank is located under the rear seat in front of the rear axle, with no access from the trunk.

Assuming you are able to locate the access door, the next step is to disconnect the negative battery cable. Then, relieve the fuel system pressure and safely drain the fuel tank. Remove the fuel tank straps that hold the tank in place and unplug the wiring harness that goes to the tank. Also, unhook any fuel lines and the filler line. With these connections removed, you can now safely remove the fuel tank assembly.

Take care to follow safety procedures when working with fuel and ensure that the area is well-ventilated.

Remove the pump from the level sensor unit

To remove the pump from the level sensor unit, carefully pull the pump up into the attaching hose or pulsator while simultaneously pulling it outward away from the bottom support. Ensure that you do not damage the rubber insulator and strainer during this process. Once the pump assembly is clear of the bottom support, pull the pump out of the rubber connector for removal.

Replace any attaching hoses or rubber sound insulator

When replacing the fuel pump on a 1991 Buick Park Avenue, you may also need to replace the attaching hoses and rubber sound insulator. Here is a step-by-step guide to help you through the process:

Replacing the Attaching Hoses:

• Verify the condition of the fuel hose: Use a flashlight and a combustible gas detector to check for any leaking fuel in the engine compartment, including the supply, return, and vapor hoses.
• Gather the necessary tools and materials: You will need a flathead screwdriver, fuel hose quick disconnect kit, fuel-resistant gloves, a fuel transfer tank with a pump, and a ratchet with metric and standard sockets.
• Prepare your vehicle: Park your vehicle on a flat, hard surface and engage the parking brake. Place wheel chocks around the front tires and use a floor jack to lift the rear of the vehicle. Lower it onto jack stands for support.
• Locate the fuel hose: If your vehicle is an older model, the fuel hose may be connected to the fuel pump, fuel tank, or carburetor. For newer vehicles, the fuel hose is typically located in the engine compartment or under the vehicle.
• Remove the old fuel hose: Place a drip pan under the fuel hose to catch any leaking fuel. Remove the hose clamps and carefully detach the hose from the fuel line, fuel pump, or carburetor.
• Clean the surface: Use a lint-free cloth to clean the area where the fuel hose was attached.
• Install the new fuel hose: Place new hose clamps around the replacement fuel hose. Ensure you have the correct size hose for your vehicle. Slide the open ends of the new fuel hose into place, checking for a proper fit. Tighten the hose clamps with a screwdriver until the hose is firmly in place.
• Reconnect the battery and pressurize the fuel system: Reconnect the ground cable to the battery's negative post. Return the fuel pump fuse to your car's fuse box to pressurize the fuel system.
• Test the vehicle: Start the engine and listen for any unusual noises. Cycle the ignition key on and off a few times to ensure all fuel lines are full. Use a combustible gas detector to check for any leaks.
• Lower the vehicle: Remove the jack stands and lower the vehicle back to the ground. Remove the wheel chocks and test drive the vehicle to ensure proper functioning.

Replacing the Rubber Sound Insulator:

• Access the fuel pump: Refer to the previous steps for locating and accessing the fuel pump in your 1991 Buick Park Avenue.
• Remove the existing rubber insulator: Carefully remove the exterior rubber sleeve or insulator from the fuel pump. This step may involve detaching any adhesive or fasteners holding the insulator in place.
• Clean and prepare the fuel pump: Ensure that the fuel pump is free of any debris or residue. You may need to use an appropriate cleaning solution and a soft cloth to wipe down the pump. Allow the pump to dry completely before proceeding.
• Install the new rubber insulator: Obtain a replacement rubber insulator or sound deadening material specifically designed for fuel pumps. Carefully fit the new insulator around the fuel pump, ensuring a snug fit. If necessary, use an appropriate adhesive to secure the insulator in place.
• Reassemble the fuel pump: Follow the reverse steps of disassembly to reinstall the fuel pump in your vehicle. Ensure that all connections are secure and that there are no leaks.
• Test the vehicle: Once the fuel pump is reassembled, start the engine and listen for any unusual noises. If the rubber insulator was installed correctly, you should notice a reduction in fuel pump noise or whine. Test drive the vehicle to ensure that it is operating normally.

Frequently asked questions