Replacing The 350Z Fuel Damper: A Step-By-Step Guide

If you're hearing a ticking or thumping noise in your Nissan 350Z, it could be a faulty fuel damper. A fuel damper is a device that softens pulsations in the stream of fuel caused by the fuel pump, reducing hydraulic noise in the fuel rails and providing a smooth stream of fuel to the injectors. A defective damper will not smooth out the flow and can result in a misfire and added noise.

To replace the fuel damper, you'll need to depressurise the fuel line, remove the engine cover, remove the air intake, and then remove and replace the fuel hose and damper. This process can take around 4 hours and requires tools such as a ratchet wrench, a 10mm socket, a socket extension, a flathead screwdriver, and a floor jack.

The fuel damper itself costs around $80, but there are also cheaper options available, and it should take around 20 minutes to install.

Removing the vacuum line

To remove the vacuum line, first, remove the vacuum line that connects the plenum to the battery cover area. This will give you some good working space.

Looking down between the strut tower and engine, you'll see a bracket that holds two fuel lines to the body. Remove those two bolts (10mm- a ratcheting wrench can be used). Then, unlock the clip that fastens the fuel damper line to the bracket.

Push the now loosened bracket toward the back of the car so that it stays out of the way. This will make your job a lot easier.

Use a long screwdriver to remove the green clip that holds the bottom of the fuel damper line to the connecting fuel line. Push down on the clip and it should come off.

Unbolt the top of the fuel damper hose. A 10mm socket with a small extension is best for this. Keep a shop towel handy to catch some minor fuel leakage.

Jack up the passenger side of the car high enough to crawl under. It is easier to remove the lower connection from under the car.

Push the green tabs together (top and bottom) and push the connector off. The green "lock" will stay on, but the larger black piece will slide off with some effort while holding those tabs down. Some fuel will drain out here, so keep a rag handy.

Disconnecting the fuel damper line

Firstly, it is important to depressurise the fuel line before removing the old fuel damper. If you skip this step, gas will spray everywhere when you remove the fuel damper. To depressurise the line, locate the fuel pump fuse under the hood, next to the battery, and remove it. Then, start the car and let it die. Crank it a few more times to relieve all the fuel pressure.

Now, you can begin to disconnect the fuel damper line. Loosen any clamps or connectors holding the fuel line in place. You may need a specialised tool for this, such as a Lisle 39210 tool or a quick disconnect tool. Be very careful not to damage the fuel line or any surrounding components. Once the line is loose, carefully lift it out of its housing.

At this point, you should be able to access the fuel damper. Before removing it, inspect it for any signs of damage or wear. Look for fuel seepage or an abnormally loud ticking noise, which could indicate a failed diaphragm. If the damper is damaged, it should be replaced.

To remove the fuel damper, you will need to disconnect it from the fuel line. This process will vary depending on your car's specific configuration, but it typically involves disconnecting the fuel line from the damper using a specialised tool or by hand. Ensure you have a rag or container ready to catch any fuel that may spill. Once the damper is disconnected, remove it from the engine bay.

Finally, you can begin the process of installing the new fuel damper and reconnecting the fuel line. This will involve reversing the steps you took to disconnect and remove the old damper. Ensure that all connections are secure and tight to prevent leaks. Once everything is connected, start the engine and check for leaks. Take the car for a test drive to ensure that the new damper is functioning correctly.

Remember to exercise caution throughout this process, as you will be working with flammable fuel. If you are unsure about any steps or feel uncomfortable performing the work yourself, consult a certified mechanic.

Depressurising the fuel line

Firstly, locate the fuel pump fuse. This is usually found under the hood, next to the battery, and is hidden behind some plastic panelling. To access it, you will need to remove the battery cover and the top trim piece by carefully popping out the plastic rivets. Be cautious when doing this, as they are fragile.

Next, pull up the weather stripping by pulling on the tabs that hold it in place. With the weather stripping out of the way, you will be able to access the fuse panel. Use a 10mm wrench to loosen the battery terminals, then remove the battery.

The fuel pump fuse will be located in the fuse panel. There are two tabs that need to be pushed in to remove the panel. Once the panel is off, you will see two more tabs on the bottom, which also need to be pushed in to remove the cover. Pull out the fuel pump fuse.

Now, put the battery back in and reconnect the terminals. Start the car and let it run until it dies. Crank the engine a further 2-3 times to ensure all fuel pressure is relieved.

Alternatively, you can skip the process of locating and removing the fuse and simply wrap a rag around the fuel damper as you remove it. However, this is not the recommended procedure and may result in fuel leakage.

Once you have depressurised the fuel line, you can move on to removing the engine cover and air intake, and then the fuel hose and damper.

Remember to exercise caution when working with fuel lines and always refer to a professional mechanic if you are unsure about any part of the process.

Removing the engine cover

To remove the engine cover as part of your 350Z fuel damper replacement, you will need a ratchet wrench and a 10mm socket.

First, remove the five bolts that hold the engine cover in place. You can do this using the ratchet wrench and 10mm socket. Once the bolts are removed, you can lift the engine cover off.

Now that the engine cover is off, you will be able to access the air intake. If your car has an aftermarket air intake, you will need to loosen the metal band connecting the throttle body. There may also be another metal band connecting a smaller inlet to the intake tube. Loosen this as well. There may also be a 10mm bolt holding the intake filter cover to the engine bay, so be sure to remove this. Finally, disconnect the Mass Air Flow sensor connector. You should then be able to lift the intake out of the engine bay.

With the air intake removed, you will have better access to the fuel hose and damper.

Disconnecting the fuel hose

Firstly, it is important to depressurise the fuel line before disconnecting the fuel hose to avoid spraying fuel everywhere. To do this, locate the fuel pump fuse under the hood, next to the battery, and remove it. You will need to remove the battery cover and the top trim piece by popping out the plastic rivets. Be careful when doing this, as they are fragile. Then, loosen the battery terminals with a 10mm wrench and pull out the battery. Remove the fuse panel and take out the fuel pump fuse. Put the battery back in and reconnect the terminals. Start the car and let it run until it dies. Crank the engine a few more times to ensure all the fuel pressure is released.

Now, you can begin to disconnect the fuel hose. Start by removing the engine cover using a ratchet wrench and a 10mm socket. If your car has an aftermarket air intake, you will need to loosen the metal band connecting the throttle body and another metal band connecting a smaller inlet to the intake tube. Disconnect the Mass Air Flow sensor connector and lift the intake out of the engine bay.

Next, you will need to remove the fuel hose and damper. Start at the opposite end of the damper and follow the fuel line to a plastic connector that holds the fuel line in place. Pop this tab open and use a metal pick to disconnect the connector from the engine bay. Push the other fuel line out of the way to access the green quick connector. Remove the green cover from the bottom of the car, which is located behind the passenger-side wheel. Push the two green tabs on the quick connector in and pull up on the fuel line to disconnect it. Keep in mind that it may be easier to have an extra pair of hands for this step.

Once the quick connector is disconnected, use a 10mm socket to remove the bolts holding the damper in place. At this point, you can install the new fuel hose and damper. Ensure you pop out the green connector and install it onto the end of the new fuel line before connecting it. Reinstall all the components in the reverse order, then start the engine to check for leaks and take the car for a test drive.

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