Replacing Fuel Pressure Sensor: Step-By-Step Guide For Diy Mechanics

The fuel pressure sensor is a crucial component of a car's engine, ensuring it receives the right amount of fuel for optimal performance and efficiency. It is usually located on the engine's fuel rail, which is responsible for distributing fuel to the fuel injectors. This sensor can fail over time, leading to various issues such as difficulty starting the engine, weak acceleration, and poor fuel mileage. Replacing it typically costs between $200 and $370, depending on the make and model of the vehicle. While it is possible to replace the sensor yourself, it is recommended to seek professional help to ensure a safe and proper installation.

Disconnect wires and remove engine intake manifold

Disconnecting wires and removing the engine intake manifold is a crucial step in accessing the fuel pressure sensor. Here is a detailed guide on how to do this safely and effectively:

Disconnecting Wires

Before beginning any work, ensure your vehicle is parked on a flat, hard surface and engage the parking brake. Start by locating the negative terminal of your car battery and disconnecting the ground cable. This will disable power to the ignition and fuel systems, ensuring your safety during the procedure.

Next, locate the fuel rail sensor. It is usually found somewhere along the engine's fuel rail, which is responsible for distributing fuel to the fuel injectors. The sensor may be tucked in on the side or right on top. Once located, proceed to disconnect the wiring harness from the fuel rail sensor. Be sure to set the harness aside safely so as not to damage it.

Removing the Engine Intake Manifold

Before removing the engine intake manifold, it is important to note that not all vehicles will require this step. If your engine has an intake that is transverse-mounted or overlaps the fuel rail sensor, then the intake must be removed to access the sensor.

To remove the intake manifold, carefully remove any brackets or components that may obstruct access to the fuel rail sensor. This may include the engine cover, depending on your vehicle's configuration. Once you have clear access, proceed to remove the mounting hardware and carefully lift the intake manifold away from the engine. Place it aside in a secure location, ensuring that you do not damage any hoses or wires attached to it.

With the wires disconnected and the engine intake manifold removed, you should now have clear access to the fuel pressure sensor. It is important to note that working on a vehicle's fuel system can be dangerous, and one should always exercise caution and refer to a professional mechanic if unsure about any steps.

Locate the fuel pressure sensor

The fuel pressure sensor is usually located somewhere along the engine's fuel rail, which is responsible for distributing fuel to the fuel injectors. This component is located somewhere on the outside of the engine. It can be tucked in on the side or right on top.

For example, in a 2013 Chevrolet Equinox, there is one fuel pressure sensor on the fuel rail that sits right behind the intake manifold, and another one underneath the engine, close to the driver's side wheel.

Some vehicles have easily accessible fuel pressure sensors that sit near the top of the engine. In a Ford Contour, the fuel pressure sensor is located on the end of the fuel supply manifold. You can find it by removing the air intake from the throttle body. It is held on by two 8mm bolts.

Before attempting to locate and replace the fuel pressure sensor, make sure that you have left your engine to cool overnight.

Remove the sensor harness and mounting hardware

To remove the sensor harness and mounting hardware, you will need a small flat-tip screwdriver, a ratchet with metric and standard sockets, and an inch-pound torque wrench.

First, ensure you have parked your vehicle on a flat, hard surface and that the transmission is in park (for automatics) or in first gear (for manuals). Next, disconnect your battery. Take the ground cable off the battery's negative post to disable the power to the ignition system and fuel system.

Now, you can remove the engine cover and any brackets that may be in the way of the fuel rail sensor. If your engine has an intake that is transverse-mounted or overlaps the fuel rail sensor, you must remove the intake before removing the fuel rail sensor.

Find the Schrader valve or test port on the fuel rail. Put on safety glasses and protective clothing. Place a small drip pan under the rail and a towel over the port. Using your small flat-tip screwdriver, open the valve by pushing on the Schrader valve. This will bleed off the pressure in the fuel rail.

Now, you can remove the harness from the fuel rail sensor. Remove the mounting hardware from the fuel rail sensor and take the fuel rail sensor off the fuel rail.

Install the new sensor

Now that you have removed the old fuel pressure sensor, it's time to install the new one. This process will involve several steps and require some tools, including a fuel hose quick disconnect kit, fuel-resistant gloves, an inch-pound torque wrench, a ratchet with metric and standard sockets, and a small flat-tip screwdriver.

First, put on your safety gear, including gloves and protective clothing. Next, install the new sensor onto the fuel rail. Screw in the mounting hardware finger-tight, then tighten it to 12 inch-pounds with a 1/8 turn. This will secure the sensor in place.

Once the sensor is mounted, plug the fuel rail sensor harness into the sensor. Reinstall any brackets or components that you had to remove to access the old sensor. If you had to remove the pressure fuel line to the fuel rail, be sure to reconnect the hose.

Finally, reinstall the engine cover by snapping it back into place. Now that the new sensor is installed, you can move on to checking for leaks and testing your vehicle to ensure the new sensor is functioning correctly.

Check for leaks and test drive the vehicle

Once you've finished replacing the fuel pressure sensor, it's important to check for leaks and test drive the vehicle to ensure that the sensor is functioning correctly. Here are some detailed steps to follow:

Check for Leaks:

• After reassembling any components that were removed or disconnected during the sensor replacement, carefully inspect all fuel lines and connections for any signs of leaks.
• Use a soapy water solution to check for leaks. Apply the soapy water to the fuel lines and connections and look for any formation of bubbles, which would indicate a leak.
• If you notice any leaks, tighten the connections or replace any faulty components as necessary.
• Ensure that the engine is turned off and allow it to cool down before performing the leak inspection.

Test Drive the Vehicle:

• Start the engine and let it idle for a few minutes. Observe the engine's behaviour and listen for any unusual noises.
• Pay attention to the warning lights on the dashboard. If the check engine light or any other warning lights come on, it could indicate a problem.
• Drive the vehicle at different speeds and on varied road conditions. Notice how the engine performs during acceleration, cruising, and idling.
• Be aware of any unusual smells, especially a strong fuel smell, which could indicate a fuel leak or an issue with the fuel pressure sensor.
• Observe the fuel efficiency and engine performance. If the fuel pressure sensor is functioning correctly, you should notice improved fuel efficiency and smoother engine performance.
• If you experience any issues such as hard starts, long crank times, rough idling, or hesitation during acceleration, it may indicate a problem with the fuel pressure sensor or another component in the fuel system.

It is important to be thorough during the test drive and take note of any unusual behaviour or symptoms. If you continue to experience problems, further diagnostics and repairs may be necessary.

Frequently asked questions