Replacing Fuel Injectors: 09 Wrx Step-By-Step Guide

Changing the fuel injectors on a 2009 WRX is a complex process that requires a range of tools and mechanical know-how. The first steps involve removing the battery, the intercooler, the TMIC, the oil filler neck, the air pump, and the driver-side TGV motor. Then, the fuel rail and injectors can be accessed and removed, with new injectors installed and the fuel rail reattached. The process must be repeated for the passenger side, with additional steps to remove and replace the coolant reservoir and intake. The entire process is time-consuming and challenging, requiring careful attention to safety and the correct procedure to avoid damage.

Disconnect the fuel pump connector and release fuel pressure

To disconnect the fuel pump connector and release the fuel pressure on a 2009 WRX, follow these steps:

Firstly, pull the fuel pump fuse and start the car, letting it idle to release the fuel pressure. You can then turn off the ignition.

Now, disconnect the fuel pump connector. This is located under the rear seat cushion. To access it, pull the cushion's side tabs towards the front of the vehicle and lift the cushion. This will reveal the metal underneath. Remove the four Phillips-head screws from the panel on the passenger side. Pull the cable holder and disconnect the plug near the passenger rear door sill to release the control cables and give you more slack. Now pull the cable and cover panel towards the footwell to move it out of the way.

Under this panel, you will see the Fuel Pump Assembly (FPA). Before disconnecting any fuel lines, it is important to release the pressure in the system. To do this, remove the eight 8mm nuts that loosen the metal ring holding the FPA. There will be some fuel spillage, so be ready to soak this up.

Now you can begin disconnecting the fuel lines by pinching the clips and pulling the lines loose. Wrap paper towels around the fuel line ends and secure them with zip ties to limit spillage. Once all three lines are disconnected, gently push them under the sheet metal to get them out of the way.

With the fuel lines disconnected, you can now remove the FPA. Be careful, as there will still be fuel in the semi-enclosed canister. Tilt the top of the canister towards the front of the vehicle as you remove it to avoid snagging the fuel level float.

Remove the battery

To remove the battery from a 2009 WRX, you will need a 10mm deep socket. The battery is located in the engine bay, and you will need to remove it before you can access the fuel injectors. Here is a step-by-step guide to removing the battery:

• Locate the battery in the engine bay. It is usually located near the front of the engine, on the side closest to the driver.
• Identify the two bolts that hold the battery in place. These bolts will be located on either side of the battery and will be visible once you have located the battery.
• Using the 10mm deep socket, loosen and remove the two bolts that hold the battery in place.
• Once the bolts are removed, you can carefully lift and remove the battery from the engine bay. Place it in a safe location, away from any flammable materials.

It is important to note that the battery is a crucial component of the vehicle's electrical system. Always handle it with care and avoid damaging the battery terminals or cables. When removing the battery, be cautious of any surrounding engine components and avoid applying excessive force.

Additionally, here are some general safety precautions to follow when working on your vehicle:

• Always wear protective gear, such as gloves and eye protection, when handling car parts.
• Ensure proper ventilation in the workspace to avoid inhaling harmful fumes.
• Keep a fire extinguisher nearby as a safety precaution when working with car parts.
• If you are unfamiliar with car maintenance, consider seeking assistance from a professional mechanic.

Remove the TMIC

To remove the TMIC, you will need to have already disconnected the battery and removed the oil filler neck. You will also need a 12mm socket with an extension, an 8mm nut driver, and pliers.

First, remove the three bolts holding the TMIC in place with a 12mm socket. Then, disconnect the hose clamp using pliers. Next, slowly lift the TMIC out of its housing, being careful not to damage any surrounding components. Finally, set the TMIC aside in a safe place, as you will need to reinstall it later.

Remove the air pump

To remove the air pump of a 2009 WRX, you will need a 12mm socket and pliers to release the clamp.

First, locate the air pump. You will need to remove the intercooler, battery, and oil filler neck to access it. The intercooler is held in place by three 12mm bolts. The battery is held in place by two 10mm bolts. The oil filler neck is held in place by three 10mm bolts.

Once you have removed these components, you should be able to see the air pump. It is held in place by two 12mm bolts and a small hose clamp. Use the 12mm socket to remove the bolts and the pliers to release the clamp. With these removed, you can carefully lift the air pump out of the engine bay.

Be sure to place a container or rag underneath the air pump to catch any fluids that may drain from it.

Remove the driver-side TGV motor

To remove the driver-side TGV motor of a 2008 WRX, you will need the following tools:

• 10mm socket(s) 1/4" & 3/8" drive
• 12mm socket(s) 1/4" & 3/8" drive
• 10mm & 12mm open-end wrench
• 2", 4", 6" extensions for 1/4" & 3/8" drive
• 1/4" & 3/8" swivels
• 10mm & 12mm ratcheting wrench
• 3/8" drive wobbler
• 1/4" drive universal joint
• 12mm flexible crowfoot
• Pliers
• 8mm nut driver or 8mm socket or flat-head screwdriver
• Needle-nose pliers

First, remove the battery. Then, remove the TMIC (this requires a 12mm socket with an extension, and 8mm nut driver, and pliers). Next, remove the oil filler neck using a 10mm socket, 10mm ratcheting wrench, and a shop towel to cover the opening.

Now, remove the air pump. This requires a 12mm socket and pliers to release the clamp.

Now you can remove the driver-side TGV motor. This is a tricky step. First, unplug the harness from the motor. Then, using a mirror, your fingers, or a magnetic pickup tool, find and remove the bottom bolt. Carefully slide the motor assembly out from the TGV gears. Once the motor is out, the 12mm back bolt will be accessible. You may need a 12mm wrench or 12mm socket and swivel to remove it.

Now you can remove the bracket. Slide it around all the hoses and wires above it.

Next, you will be able to get to the plugs that go to each of the injectors. Use needle-nose pliers, or squeeze the plug with your fingers to remove them.

Now, remove the two 12mm bolts that hold the fuel rail in place. Remove the bolts, then slowly pull the bracket up to release the injectors (and fuel). You may also need to loosen or remove the 10mm bolts holding the hardline fuel piping on top of the manifold.

Once you get the rail high enough to remove the injectors, carefully remove them. They are loosely sandwiched between the fuel rail and the intake manifold. Once you have removed both injectors, take a look to see if you have grabbed all of the o-rings that were on the injectors. The new injectors come with new o-rings, so all of the old ones must be removed. Use an automotive pick to remove them if needed.

Now you can install the new injectors. It is best to apply some synthetic grease with PTFE or petroleum jelly to the top o-ring to easily slide it into the rail. Just a very small amount will do. Place the fuel injectors in the TGV housing and push the injector into the rail, being careful that everything is sealed to the fuel rail. The top o-ring should provide a tight fit so that it cannot be too easily pushed out of the rail or fall out of it.

Bolt down the fuel rail to the TGV with the two bolts. Be careful not to cross-thread the bolt. Tighten by hand with the extension to confirm that you can easily spin the bolt. Do not tighten all the way until you get the second bolt threaded, or the second bolt may not go in easily. After both bolts are threaded, tighten both down by hand and tighten the fuel rail bolts.

Now you can reinstall the bracket.

Frequently asked questions