Replacing The Fuel Pump In A 3000Gt: Step-By-Step Guide

Changing the fuel pump on a Mitsubishi 3000GT is a task that sounds harder than it is. While it may be challenging to loosen the fuel-line fittings, it is possible to do so without removing the gas tank. This job can be made easier by raising the car, although it is not necessary. Before starting, ensure you have the right tools for the job, including a #2 Phillips screwdriver, a flat-blade screwdriver, a 14-mm open-end or flare-nut wrench, and a 19-mm open-end wrench. It is also recommended to have less than a quarter of a tank of fuel.

Prepare your tools: Phillips screwdriver, flat-blade screwdriver, 14-mm wrench, 19-mm wrench, 8-mm and 7-mm sockets, and a knife

To prepare your tools for changing the fuel pump on a Mitsubishi 3000GT, you will need a few specific tools to get the job done. Firstly, get your hands on a #2 Phillips-head screwdriver. You will also need a standard, flat-blade screwdriver. Next, you should gather your wrenches: a 14-mm open-end or flare-nut wrench and a 19-mm open-end wrench. Additionally, you will require some sockets: specifically, 8-mm and 7-mm sockets, along with a ratchet. Finally, a thin-bladed knife, such as a pocket knife, will be needed.

It is worth noting that a hand impact tool and a hammer may also come in handy during this process, although they are not essential. Having a variety of wrenches and sockets will ensure you can tackle the various fittings and connections on the fuel pump assembly. The Phillips-head screwdriver will be useful for removing the access cover to the pump assembly, while the flat-head screwdriver will be used for prying off certain components during the removal and installation of the new pump. The thin-bladed knife will help with gently prying off the washer that holds the filter in place.

Remove rear seats, storage, and carpet for easier access

To remove the rear seats, storage, and carpet for easier access to the fuel pump, follow these steps:

First, put on your safety glasses and keep a fire extinguisher nearby. Next, disconnect the negative battery cable. Relieve the fuel system pressure following the procedure in the factory repair information.

Now, it's time to remove the rear seats. This process may vary depending on your car's model and year, but typically, you will need to remove the rear seat cushion or the entire rear seat. You may need to remove bolts or other fasteners holding the seat in place. Once the seat is removed, set it aside carefully.

With the rear seat removed, you will have access to the storage and carpet. Remove any necessary bolts or fasteners holding the storage compartments in place and carefully lift them out. Now, you can start peeling back the carpet. Be gentle, as you don't want to damage it. Work your way towards the front of the car, peeling back the carpet as you go.

At this point, you should have sufficient access to the fuel pump. Remember to consult the factory repair manual for your specific vehicle for more detailed instructions and safety precautions.

Disconnect electricals and reduce fuel-line pressure

Disconnecting the electricals and reducing the fuel-line pressure are crucial steps when changing the fuel pump on a Mitsubishi 3000GT. Here's a detailed guide on how to approach these steps:

Disconnecting the Electricals:

Before beginning any work on your Mitsubishi 3000GT's fuel pump, it is essential to disconnect the electrical connection to the pump. This step is crucial for safety reasons and ensures that there is no power to the pump during the replacement process. Here's how to do it:

• Locate the electrical connection for the pump. It is usually found at the rear of the blue, two-way valve.
• Press down on the top tab of the connector and pull it forward to unplug the electrical connection.
• Attempt to start the car. If the electrical connection has been successfully disconnected, the car should not start.

Reducing Fuel-Line Pressure:

Reducing the fuel-line pressure is important to minimize the risk of fuel leakage during the pump replacement process. Here's a step-by-step guide to reducing the fuel-line pressure:

• Remove the blue, two-way valve by sliding it up and off its mounting post on the top of the fuel pump assembly.
• Loosen the clamp on the back hose connected to the valve and slide the hose off. You may need to twist the hose to remove it completely.
• Address the high-pressure fuel line. This is a challenging part, as the fittings tend to be tight and may require some force to loosen. Use a 14-mm flare-nut wrench or an open-end wrench to hold the fixed bolt on the metal pipe.
• Use a 19-mm open-end wrench to loosen the nut on the hose. Apply force by pushing or pulling the wrench toward the outside (passenger side) of the car. Be cautious not to bend or move the metal pipe and "bolt."
• If needed, access the other end of the hose in front of and above the gas tank. Loosen the fitting using the appropriate wrench sizes (19-mm for the hose nut and 14-mm for the metal pipe "bolt").
• Note: It is not necessary to completely disconnect this fitting; simply loosening it should suffice.
• Always wear safety goggles when working underneath the car to protect your eyes from any fuel spray or debris.
• If you encounter rusted or seized connections, consider using penetrating oil (e.g., WD-40, PB Blaster, or Liquid Wrench) to help loosen the fittings.

Remember, working with fuel lines can be dangerous, so take your time, wear protective gear, and ensure you have the necessary tools and knowledge before proceeding.

Remove the high-pressure fuel line

Removing the high-pressure fuel line is a crucial step in changing the fuel pump on a Mitsubishi 3000GT. Here is a detailed guide on how to do it:

First, locate the high-pressure fuel line. It is attached to the metal pipe coming out of the fuel pump assembly. You will notice what looks like two nuts or a bolt and a nut at the end of the metal pipe. The "bolt" is fixed to the metal pipe and does not turn, while the "nut" is attached to the rubber hose.

To remove the high-pressure fuel line, follow these steps:

• Attach a 14-mm flare-nut wrench or an open-end wrench to the fixed "bolt" on the metal pipe. This will prevent it from moving or bending while you loosen the "nut".
• Use a 19-mm open-end wrench to loosen the "nut" on the rubber hose. Push or pull the wrench toward the outside (passenger side) of the car to loosen it.
• Once the "nut" is loose, you may be able to completely remove it by twisting the rubber hose multiple times. However, it is usually easier to loosen the fitting at the other end of the hose, which is located in front of and above the gas tank.
• Loosen the fitting at the front of the hose using the same wrench sizes: 19-mm on the hose "nut" and 14-mm on the metal pipe "bolt". Remember that the bolt rotates counterclockwise, and the nut rotates clockwise when you are laying on your back, head towards the front of the car, looking up at the fitting.
• It is not necessary to completely disconnect this fitting; simply loosen it. Be sure to wear safety goggles when working underneath the car.

Alternatively, as some users have suggested, you can leave the high-pressure line attached to the pump assembly and remove the forward end of the hose near the front of the fuel tank. Then, remove the hose with the assembly, which will require a bit more manoeuvring.

Remove and replace the fuel pump assembly

Before starting, ensure you have the following tools: a no. 2 Phillips screwdriver; a flat-blade screwdriver; a 14-mm open-end or flare-nut wrench; a 19-mm open-end wrench; 8-mm and 7-mm sockets and a ratchet; and a thin-bladed pocket knife. A hand impact tool and hammer could also be useful.

First, reduce the fuel line pressure. Unplug the electrical connection for the pump (to the rear of the blue, two-way valve). It is connector F-16 in the electrical configuration and circuit diagrams. Press down on the top tab and pull it forward. Now try to start the car. It shouldn't.

Next, remove the blue, two-way valve. Slide the valve up and off its mounting post on top of the fuel pump assembly. Slide the clamp on the back hose off the valve and slide the hose off the valve (twisting can help).

Now, remove the high-pressure fuel line. This is at the end of the metal pipe coming out of the assembly. There will be two nuts there (or a bolt and a nut). The "bolt" is fixed to the metal pipe and does not turn. The "nut" is attached to the rubber hose. Attach a 14-mm flare-nut wrench (or an open-end wrench) to the fixed bolt on the metal pipe. Use a 19-mm open-end wrench to loosen the nut on the hose by pushing or pulling the wrench toward the outside (passenger side) of the car. Make sure that the "bolt" and metal pipe do not move or bend.

Once the nut is loose, you may be able to remove it by twisting the rubber hose. However, it is easier to loosen the fitting at the other end of the hose, in front of and above the gas tank. Loosen the fitting using the 19-mm wrench on the hose "nut" and the 14-mm wrench on the metal pipe "bolt". The bolt rotates counterclockwise and the nut clockwise, as you are laying on your back, head towards the front of the car, looking up at the fitting. It is not necessary to disconnect this fitting; just loosen it. Be sure to wear safety goggles when working underneath the car.

Note: It may be easier to leave the high-pressure line attached to the pump assembly and remove the forward end of the hose (near the front of the fuel tank). Then, the hose is removed with the assembly. The assembly must be manoeuvred a bit more than in the procedure described above.

Now, remove the six 8-mm nuts on top of the assembly. The pump assembly is now ready to lift out. Note the three rubbery protrusions along the edge of the assembly top. These are part of a rubber gasket that goes between the assembly top and the compartment floor. Use your fingers to ensure this gasket does not tear as you remove the assembly. You will have to rotate and tilt the assembly to get it out of the tank.

Drain the fuel out of the assembly. Let the fuel drain out of the top and bottom of the assembly. Do not bend the wires attaching the float and low-level sensor while handling the assembly.

To finish, remove the filter, pump, and transfer parts to your replacement pump.

Frequently asked questions