Changing The Fuel Pump In A Geo Prizm: Step-By-Step Guide

If you're looking to replace the fuel pump in your Geo Prizm, it's important to know that this component is located inside the fuel tank. While it's possible to access the pump through an access panel above the tank in the passenger compartment, you may need to drain the fuel and lower the tank if no access panel exists. The fuel pump plays a crucial role in supplying pressurised gasoline to the fuel injectors, and its failure can lead to issues such as the car not starting or stalling unexpectedly. Before replacing the pump, a qualified mechanic should test it to confirm that it is faulty. Additionally, whenever the fuel pump is replaced, it is recommended to install a new fuel filter as well.

Fuel pump location

The fuel pump in a Geo Prizm is located inside the fuel tank. If your car has gasoline direct injection (GDI), there will also be a second, high-pressure pump near the fuel rail in the engine compartment.

To access the fuel pump, you will need to lift up the back seat. There should be four screws holding a plate with electrical wires. Remove the screws and lift the plate. Now you can replace the fuel pump without dropping the fuel tank.

Alternatively, you may need to remove the fuel tank from the vehicle to access the pump.

Fuel filter location

The fuel filter on a Geo Prizm is located on the driver's side of the front firewall. Follow the hose from the fuel rail to the filter. The fuel pump is located inside the fuel tank.

For a 1994 Geo Prizm with a 1.6L engine, the fuel filter is located on the driver's side of the firewall, directly below the brake master cylinder, bolted to a black bracket.

To replace the fuel filter, you will need a 14mm wrench to disconnect the fuel line from underneath by the driver's front wheel, a 17mm to remove the upper fuel line, and a 10mm to remove the fuel filter from the bracket by the firewall on the driver's side.

There are a variety of fuel filters available for the Geo Prizm, including:

• Duralast Fuel Filter FF716DL
• Duralast Fuel Filter FF722DL
• ACDelco Fuel Filter GF629
• Fram Fuel Filter G6674
• Fram Fuel Filter G7612

Tools required

To change the fuel pump on a Geo Prizm, you will need a variety of tools to complete the job. Here is a list of the tools required:

• A set of wrenches in various sizes, including 10mm, 14mm, and 17mm. These will be needed to disconnect and remove fuel lines and the fuel filter.
• A mechanic's tool kit, including screwdrivers, sockets, and other basic tools for automotive repair.
• A fuel pressure gauge to relieve the pressure in the fuel system before disconnecting the fuel lines.
• A container to catch any fuel that may spill or leak during the process.
• A jack or lift to raise the vehicle and gain access to the fuel filter and lines.
• A new fuel filter, fuel pump, and any necessary gaskets or seals.
• Safety equipment, including eye protection, gloves, and a respirator to protect yourself from fuel and any debris.

It is important to have the correct tools and safety equipment before attempting to change the fuel pump on your Geo Prizm. Working on a fuel system can be dangerous, so it is always best to be prepared and take the necessary precautions.

Signs of a failing fuel pump

The fuel pump is responsible for delivering gasoline from the fuel tank to the fuel injectors. A failing fuel pump will not be able to create enough pressure in the fuel system, which may cause the engine to lose power or the car to not start at all. Here are some signs that indicate a failing fuel pump:

• Whirring noise from the fuel tank area: As the fuel pump fails, you may notice a whirring or humming noise coming from the rear of the car, near the fuel tank. If this noise is coming from the fuel pump, it is likely that the pump will fail soon and should be replaced as soon as possible.
• Car won't start or unexpectedly stalls: A failing fuel pump may prevent your car from starting or cause it to stall unexpectedly. This is often due to the pump not being able to deliver adequate pressure or fuel to the engine.
• Check engine light is on: If the fuel pump is failing slowly, the fuel pressure and volume will gradually decrease. This lack of fuel can cause the engine to operate with an insufficient amount of fuel relative to the air, triggering the check engine light.
• Loss of engine power: A failing fuel pump may not be able to deliver enough fuel or pressure to the engine, resulting in a loss of engine power.
• Engine overheating: While it is generally safe to drive with a failing fuel pump, it may lead to an overheated engine and catalytic converter.

If you notice any of these signs, it is recommended to have your fuel pump checked and potentially replaced by a qualified mechanic to avoid being stranded with a car that won't start.

Fuel pump replacement process

Step 1: Locate the fuel pump

The fuel pump in a Geo Prizm is located inside the fuel tank. To access it, you can either remove an access panel above the tank in the passenger compartment or drain the fuel tank and lower it from the vehicle.

Step 2: Remove the fuel pump

Once you have located the fuel pump, you will need to remove it from the fuel tank. This involves disconnecting the fuel pump supply and return hoses, EVAP system hoses, and electrical connections.

Step 3: Install the new fuel pump

Before installing the new fuel pump, check if your fuel system uses an in-line external filter. If it does, you should replace the filter. Then, attach any reusable brackets and pick-up screens to the new fuel pump and install it in the fuel tank. Re-establish all hoses and electrical connections.

Step 4: Test the new fuel pump

After installing the new fuel pump, add fuel to the tank and run the engine to test for leaks. Make sure to keep the gas tank at least a quarter full to maximize the life of the new fuel pump.

Safety precautions:

• Prior to replacing the fuel pump, power it directly to confirm that the issue is a faulty pump and not a faulty power supply.
• Unless the fuel filter was replaced recently, replace it when installing the new fuel pump.
• Check the fuel tank straps and fasteners for excessive corrosion and replace them if needed.

Frequently asked questions