Changing Fuel Filter In 2003 Mitsubishi Eclipse: Step-By-Step Guide

The fuel filter in a 2003 Mitsubishi Eclipse is part of the fuel pump assembly and is located inside the gas tank. While some sources claim that the fuel filter does not need to be replaced, others suggest replacing it every 60,000 miles or every 100,000 miles. To replace the fuel filter, you will need to remove the rear seat cushion, disconnect the fuel pump harness connector, relieve the fuel system pressure, and then remove and replace the fuel filter before reassembling the components.

Removing the rear seat

To remove the rear seat of a 2003 Mitsubishi Eclipse, first open the car doors and hatch to ventilate the area. Gas fumes can be toxic, so it is important to ensure the area is well-ventilated. Do not smoke during this process.

Next, locate the two tabs in the middle section of the left and right seats (not in the middle of the back seat). Pull these tabs and then pull the seat up. This will allow you to access the fuel pump.

Now, you need to remove the metal plate (lid plate) towards the center of the rear seat area. There are four screws (one on each corner) and a wire running through the middle of the plate. Remove the screws and carefully lift the plate off its base.

At this point, you will see two wiring harnesses that need to be unplugged. Be cautious and wear eye protection during the following steps as you will be working with the fuel line, which is pressurized and prone to spray if the car hasn't been sitting for 24 hours or more.

Now, remove the fuel line and the fuel return line. These are the only two hoses connected to the assembly. Mark a line on the black plastic ring directly across from the green circle with a white marking pen. This will ensure that you can line up the ring in the same spot when you reinstall it.

Using a flat-head screwdriver and a rubber mallet, gently tap the screwdriver against the bottom of the black ring until you can remove it. Be careful not to break this piece. With the black ring removed, you can now access the fuel pump assembly.

Disconnecting the fuel pump

Release Fuel Pressure

First, you need to release the fuel pressure in the system. Open the car doors, hatch, and garage door (if applicable) to ensure proper ventilation. Gas fumes can be toxic, so adequate ventilation is essential. Remove the rear seat cushion by pulling the tabs located in the middle section of the left and right seats. This will expose the unpainted panel, which is the fuel pump access cover. Loosen and remove the four bolts holding this cover and pull it up to expose the fuel pump.

Disconnect Wiring Harness

Now, locate the wiring harness that plugs into the fuel pump. Press the locking button and pull up on the harness to unplug it.

Run the Vehicle Until it Stalls

Insert the key into the ignition and start the vehicle. Let the car run until it stalls. This step is crucial as it ensures that all fuel pressure is eliminated from the lines. Once the vehicle stalls, turn the key to the "Off" position.

Disconnect the Negative Battery Cable

Open the hood of your Eclipse and locate the negative battery cable. Using a ratchet and socket, disconnect this cable.

Disconnect Fuel Lines

The next step is to disconnect the fuel lines from the fuel filter. Loosen and remove the main fuel line into the bottom of the fuel filter using two line wrenches. One wrench is used to turn the nut on the line, while the other holds the connector on the fuel filter.

By following these steps, you will have successfully disconnected the fuel pump on your 2003 Mitsubishi Eclipse, preparing you for the next steps in changing the fuel filter. Remember to work in a well-ventilated area and wear eye protection to ensure your safety during this procedure.

Removing the fuel filter

To remove the fuel filter from a 2003 Mitsubishi Eclipse, you will need to first relieve the fuel system pressure. Open all car doors, the hatch, and the garage door if you are in one, as gas fumes can be toxic and require good ventilation. Do not smoke during this process.

Remove the rear seat by pulling the two tabs located in the middle section of the left and right seats (not the middle of the back seat). Then, remove the metal plate (the lid plate) toward the centre of the rear seat area. There will be four screws (one on each corner) and a wire running through the middle of the plate. Remove the screws and lift the plate off its base.

Unplug the two wiring harnesses that you'll find once you've removed the plate. Be extremely cautious and wear eye protection during the following steps, as the fuel line is pressurized and prone to spray if your car hasn't been sitting for 24 hours or more.

Mark a line on the black plastic ring directly across from the green circle with a white marking pen. This will ensure that you can line up the ring in the same spot when you re-install it. Remove the black ring encircling the assembly using a flat-head screwdriver and a rubber mallet. Gently tap the screwdriver against the bottom of the black ring with the mallet until you can remove it.

Pull the fuel pump assembly out of the gas tank by pulling straight up and then angling it to the right once you feel resistance. There is a bobber attached to the bottom that will snag when you pull it up. Simply angle the fuel pump to free it. Don't force it.

Place the fuel pump into a bucket to avoid dripping gasoline into the rear seat area. Separate the fuel pump (black) and the fuel reservoir (white or tan) by pushing and pulling apart the three tabs.

The fuel filter can now be removed from the fuel reservoir.

Installing the new fuel filter

First, separate the fuel pump (black) and the fuel reservoir (white or tan) by pushing the three tabs and pulling them apart. Then, remove the old fuel filter from the fuel reservoir and insert the new one. Next, connect the fuel pump and the fuel reservoir by lining them up and pushing until the tabs lock.

Now, reconnect the electrical plugs in their respective places on the fuel pump and fuel reservoir. The plugs will only plug into the holes they are meant for, so don't force one if it doesn't seem to fit. Insert the bobber into the fuel pump at an angle, then turn the fuel pump straight to drop it in the gas tank. Put the black ring back over the assembly and use the rubber mallet and screwdriver to tap it into place. Line up the line you drew on the black ring with the marking pen and the green triangle on the outside of the ring.

Finally, connect both fuel hoses and the electrical plugs. Replace the lid plate and screw the four screws into place. Then, replace the rear seat by setting it in place and pushing down until the tabs lock.

Reattaching the rear seat

To reattach the rear seat of a 2003 Mitsubishi Eclipse, follow these steps:

Firstly, ensure the fuel pump is placed back into the gas tank. The fuel pump is located under the rear seat. Next, replace the lid plate and screw the four screws into place. Now, reconnect the negative battery cable. Then, place the rear of the rear seat cushion under the seat-back cushion, and push the front of the cushion down until it clicks into place. The rear seat should now be securely reattached.

Please note that this process involves working with fuel and electrical components, so it is important to take appropriate safety precautions, including working in a well-ventilated area and wearing eye protection.

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