Replacing Fuel Pump In Vt Commodore: Step-By-Step Guide

If your Holden VT Commodore is experiencing issues such as poor engine performance, reduced fuel economy, or even complete engine failure, it may be time to replace the fuel pump. The fuel pump is responsible for transferring fuel from the tank to the fuel injectors, ensuring the engine runs smoothly. While it is an important component, replacing it doesn't have to be a difficult task. With the right tools and some mechanical know-how, it is possible to replace the fuel pump yourself, saving you time and money. In this guide, we will walk you through the process of replacing the fuel pump in your VT Commodore, covering everything from the necessary precautions to the step-by-step installation process.

Prepare your Commodore and work area

Park your Commodore on a flat, level surface and engage the parking brake. Allow the engine to cool if it has been running recently. If your Commodore has a full tank of fuel, consider draining some of the fuel to reduce the weight of the fuel tank, making it easier to work with.

Gather the necessary tools and safety equipment, including gloves and eye protection. Place a suitable receptacle under the fuel tank to catch any spilled fuel during the removal process.

Jack up the rear of the car and place jack stands underneath for support. Ensure the vehicle is stable and secure before proceeding. You may also want to use a hoist to make the job easier, especially when taking the fuel tank out and putting it back in. Additionally, consider using a bench or stand under the fuel tank for added convenience.

Disconnect the negative battery terminal to prevent any accidental electrical discharge. Remove the fuel pump relay as a precautionary measure.

Remove the fuel tank

To remove the fuel tank from a VT Commodore, follow these steps:

Firstly, depressurise the fuel system and ensure there are no naked flames or ignition sources nearby. Siphon the fuel from the tank using commercially available equipment. Never drain or store fuel in an open container to avoid the risk of fire or explosion.

Next, raise the vehicle using a hoist if possible. If you don't have access to a hoist, you can jack up the differential and place the car on stands. Remove the three stone guard retaining screws and take off the stone guard from under the right-hand rear guard.

Disconnect the electrical connectors and hoses from the fuel system. Remove the fuel sender electrical connector by pulling it forward to dislodge it, then depress the locking tab to separate the connector halves. Place a drain tray under the fuel filter area, ensuring that all dirt and foreign material is removed from the fuel connections before removal.

Disconnect the quick-connect fittings to the vapour canister, return line, and fuel filter. To do this, push inward to release the seal pressure, depress the side tangs of the connector, and then pull to disconnect. Disconnect the vapour canister breather hose at the canister. If necessary, remove the fuel filter by detaching the fuel feed line quick connector and depressing the two barbs on the mounting strap nipple. Caution: fuel will spill from the disconnected filter.

Disconnect the earth strap from the spade connector, located under the front right-hand strap mounting bolt of the right-hand tank support strap. Now, remove the fuel tank support straps. Start by removing the centre strap by taking off the rear retaining nut and washer, then unhook the strap from the front support. While supporting the fuel tank in the centre, remove the strap closest to the filler neck by taking off the bolt at the front and unhooking the strap from the rear support. Finally, remove the last strap by taking off the nuts and washers from each end.

With the straps removed, carefully lower the fuel tank from the vehicle, left side first, to release the fuel filler neck from the body opening. From here, you can access and replace the fuel pump. Reinstallation is the reverse of the removal process. It is helpful to have an assistant when performing these tasks.

Disconnect the fuel pump assembly

Disconnecting the fuel pump assembly in a VT Commodore is a detailed process that requires careful attention to safety and specific tools. Here is a step-by-step guide to help you through the process:

Firstly, make sure to run the car until the fuel light comes on and then a little more to ensure the tank is as empty as possible. This is an important precautionary step to avoid the risk of spilling fuel when you start working on the fuel pump. Once this is done, remove the fuel pump relay and disconnect the battery, even though this is not necessary, it is a good safety measure.

Now, you can begin the process of accessing the fuel pump assembly. Raise the vehicle using a hoist or car stands to gain access to the underside of the car. Position a jack under the fuel tank to support it. Undo the fuel tank clamp bolts and remove the brackets. Slowly lower the fuel tank, taking care not to spill any remaining fuel.

At this point, you will need a special fuel line disconnect tool to disconnect the fuel lines from the sender unit. You can purchase this tool from automotive stores like Repco or Supercheap Auto. Alternatively, you can slice the end of a water bottle or use a chalk gun silicone/no nails cap to create a makeshift tool. Be sure to release the pressure in the fuel lines before attempting to remove the clips.

With the tool in hand, carefully disconnect the fuel, return, and vapour lines from the sender unit. Also, remove the breather from the filler neck. Now, you can lower the tank completely and place it on the floor. Undo the metal securing bracket on top of the sender unit and carefully lift it out of the tank.

At this stage, you will have access to the fuel pump and can proceed with the replacement process. Remember to work cautiously and refer to detailed guides or videos if you need further clarification on any steps.

Install the new fuel pump

To install the new fuel pump in your VT Commodore, you will first need to ensure you have purchased the correct pump for your vehicle. The fuel pump is located inside the fuel tank, so you will need to remove the tank from the car. This can be done using a hoist, car ramps, or chassis stands, keeping in mind that accessing the pump may be easier with a hoist or car ramps.

Once the tank is out, you can begin the process of replacing the fuel pump assembly. This typically involves removing the old pump and installing the new one, ensuring that all connections are secure and any necessary seals are in place. Be cautious when handling the pump, as the fuel tank will likely contain some fuel. It is recommended to run the car until the fuel light comes on to minimize the amount of fuel in the tank.

When installing the new fuel pump, refer to the manufacturer's instructions or a repair manual for specific details on the process. Ensure that the new pump is compatible with your vehicle and that all necessary parts are included in the assembly. If you are unsure about any aspects of the installation, it is best to consult a professional mechanic or seek advice from a trusted source.

After installing the new fuel pump, you will need to reattach the fuel tank to the vehicle and reconnect any disconnected components, such as the fuel pump relay and battery. Be sure to follow safety precautions and refer to a repair manual if needed. Once the installation is complete, you can start the car and test the new fuel pump to ensure it is functioning properly.

Reattach the fuel tank

To reattach the fuel tank, you will need to ensure that the new fuel pump is correctly installed. This involves more than just dropping the tank back into the car. You must ensure that the fuel pump assembly is securely attached to the tank and that all fuel lines and electrical connections are properly connected.

It is important to note that the fuel pump is located at the top of the tank in VT Commodores, so you will need to work from underneath the car. Using a hoist or car ramps will make this process much easier. Once you have accessed the fuel tank, you can begin the process of reattaching it.

Firstly, you will need to ensure that the fuel pump assembly is securely attached to the tank. This may involve using bolts or other fasteners to attach the assembly to the tank. It is important to refer to the manufacturer's instructions or a repair manual for specific instructions on attaching the fuel pump assembly.

Next, you will need to connect the fuel lines to the fuel pump. These lines will carry fuel from the tank to the engine, so it is important to ensure that the connections are secure and free of leaks. You may need to use quick-connect fittings or clamps to attach the fuel lines to the fuel pump.

Finally, you will need to connect the electrical components of the fuel pump. This may involve plugging in a wiring harness or connecting individual wires to the fuel pump. Ensure that all connections are secure and that there is no damage to the wiring. Once all the connections are made, you can lower the fuel tank back into the car and secure it in place.

Frequently asked questions