Ford Taurus Fuel Line: Understanding Pressure Performance

The fuel pressure in a Ford Taurus is a common issue among owners of the vehicle. The problem can be caused by a faulty fuel pump, a clogged fuel filter, or a faulty fuel pressure regulator. The fuel pressure should be around 40 psi most of the time, according to some Taurus owners. However, others have reported readings ranging from 30 to 55 psi with the key on and the engine off, and 26 to 45 psi with the engine on. It is important to note that the fuel pressure readings may not match between a mechanical gauge and the fuel rail pressure sensor. This is because the sensor is referenced to manifold vacuum, while the mechanical gauge is referenced to atmospheric air.

Fuel pressure problem and pressure specs

The fuel pressure on a Ford Taurus is an important factor in maintaining the vehicle's performance and fuel efficiency. The ideal fuel pressure can vary depending on the specific model and year of the Ford Taurus, as well as other factors such as engine speed and load.

For a 2004 Ford Taurus 3.0L OHV VIN "U", the standard fuel pressure listed is 30-55 psi key on engine off and 26-45 psi engine on. However, one owner reported readings of 60 to 61 psi key on engine off and 55 to 57 psi at idle. This discrepancy could be due to variations in fuel pressure sensors or other factors.

On a 2000 SE OHV Taurus, the fuel pressure can be checked using a Shrader valve located on the right side of the fuel rail. This valve can be accessed by removing a protective screw-on cap. A fuel pressure gauge can then be attached to the valve to measure the pressure.

For a 2004 Sable with a 3.0 24-valve twin cam motor, there is no Schrader valve, as these were discontinued in some models after 2002. Instead, fuel pressure can be checked using a scanner that can access the pressure monitor. Alternatively, the fuel pump relay can be pulled, or a clip can be disconnected from the filter to drain the fuel back.

According to Ford forums, the fuel pressure should ideally be around 40 psi most or all of the time. However, this can vary depending on driving conditions and other factors. A weak fuel pump or a faulty Fuel Rail Pressure Sensor (FRPS) could cause low fuel pressure, resulting in codes such as P0191, P0171, and P0174.

In summary, the fuel pressure on a Ford Taurus can vary depending on the model, year, and driving conditions. It is important to refer to the specific specifications for your vehicle and consult a mechanic or a Ford forum for accurate information and troubleshooting advice.

Fuel rail pressure sensor circuit performance

The fuel rail pressure sensor circuit performance of a Ford Taurus is an important aspect of the vehicle's fuel system. This sensor plays a crucial role in ensuring the engine receives the correct amount of fuel for optimal performance. Here is some detailed information about the fuel rail pressure sensor circuit performance in a Ford Taurus:

Symptoms of a Faulty Fuel Rail Pressure Sensor

A faulty fuel rail pressure sensor in your Ford Taurus can cause various issues, including poor fuel mileage, a illuminated check engine light, difficulty starting the engine, and weak acceleration or stalling. These problems can be frustrating and impact the overall drivability of your vehicle.

Function of the Fuel Rail Pressure Sensor

The fuel rail pressure sensor in your Ford Taurus is responsible for monitoring the pressure of the fuel in the fuel rail, which is the tube that carries fuel to the engine's injectors. By measuring the pressure, the sensor ensures that the correct amount of fuel is delivered to the injectors, allowing for precise fuel injection and optimal engine performance.

Testing and Replacement

If you suspect that your Ford Taurus is experiencing issues related to the fuel rail pressure sensor, it is recommended to have it tested by a qualified mechanic or automotive technician. They can use specialised tools and diagnostic equipment to check the sensor's performance and identify any faults. In some cases, cleaning the sensor may improve its functionality, but if it is severely damaged or faulty, replacement may be necessary.

Available Replacement Sensors

There are several replacement fuel rail pressure sensors available in the market that are compatible with the Ford Taurus. These sensors are designed to match the original equipment specifications and ensure proper fit and functionality. Reputable brands such as Bosch, Carquest Premium, Dorman, and Duralast offer replacement sensors that can help restore the fuel system's performance and resolve issues related to fuel pressure.

Preventative Measures

To maintain the fuel rail pressure sensor's performance and longevity, it is essential to use high-quality fuel and maintain proper fuel filter maintenance. Contaminated fuel or a clogged fuel filter can affect the sensor's accuracy and performance over time. Regular fuel system maintenance can help prevent sensor-related issues and ensure the optimal operation of your Ford Taurus.

Fuel pressure test

To perform a fuel pressure test on a Ford Taurus, you will need to locate the fuel rail pressure sensor, which is usually found on the fuel rail itself. On some models, there may be a Schrader valve on the right side of the fuel rail, which you can use to connect a mechanical fuel pressure gauge. However, on newer models, there may not be a Schrader valve, and you will need to use a scan tool to read the fuel pressure sensor data.

• Locate the fuel rail: The fuel rail is typically located on the top of the engine, running parallel to the cylinders. It is a metal tube that supplies fuel to the fuel injectors.
• Identify the fuel rail pressure sensor: The sensor is usually located on the fuel rail itself and may have a Schrader valve or a test port.
• Connect a mechanical fuel pressure gauge (if applicable): If your vehicle has a Schrader valve, you can rent a fuel pressure testing kit from an auto parts store. Connect the gauge to the Schrader valve and ensure that the valve is open.
• Start the engine and observe the fuel pressure: With the engine running, observe the fuel pressure reading on the mechanical gauge or the scan tool. The fuel pressure should be within the specified range for your particular model of Ford Taurus.
• Compare the reading to the specified fuel pressure: The specified fuel pressure for your Ford Taurus may vary depending on the year and model. For example, for a 2004 Ford Taurus 3.0L OHV, the specified fuel pressure is 30-55 psi with the key on and engine off, and 26-45 psi with the engine on.
• Perform further diagnostics if necessary: If the fuel pressure is outside the specified range, you may need to troubleshoot potential issues such as a weak fuel pump, a faulty fuel pressure regulator, or a clogged fuel filter.

It is important to note that fuel pressure readings from a mechanical gauge may not match the readings from the fuel rail pressure sensor, especially on newer Ford Taurus models with electronic fuel injection systems. This is because the mechanical gauge measures pressure relative to atmospheric air, while the fuel rail pressure sensor measures pressure relative to manifold vacuum. Therefore, it is recommended to use a scan tool to read fuel pressure data whenever possible.

Releasing fuel pressure

Step 1: Locate the Fuel Pump Relay

The fuel pump relay is located in the fuse box, which is a black plastic box behind the radiator. There will be a cable running from the positive battery terminal to the fuse box. One of the fuses in this box controls the fuel pump.

Step 2: Remove the Fuel Pump Relay

With the car off, remove the fuel pump relay from the fuse box. The relay for the fuel pump is usually labelled or numbered, so check your car manual to identify the correct fuse. Once you have located the correct fuse, simply pull it out of the fuse box.

Step 3: Run the Engine Until it Stalls

After removing the fuel pump relay, get into your car and start the engine. Without the fuel pump relay, the engine will eventually stall as it runs out of fuel. This may take a few minutes, so be patient.

Step 4: Crank the Engine for 5-10 Seconds

Once the engine has stalled, crank the engine by turning the key in the ignition to the "Start" position for 5-10 seconds. Do not start the engine, simply crank it to relieve any remaining pressure in the fuel lines.

Step 5: Reinstall the Fuel Pump Relay

Finally, put the fuel pump relay back into the fuse box and start your car as normal. The fuel pressure in your Ford Taurus should now be released, and you can proceed with replacing your fuel injectors.

It is important to exercise caution when working with fuel systems. Always ensure the engine is off and cooled down before removing any fuel-related components. If you are unsure about any steps, consult a qualified mechanic.

No start, checking fuel pressure

If your Ford Taurus won't start, there are a few things you can check to diagnose the problem.

First, check for spark and fuel. If you have a spark, but no fuel, you may have a bad fuel pump. You can test this by listening for the pump to run for about one second when you key to run but don't crank. If the pump doesn't run, you likely have a pump or module issue. If it runs and then stops, key to off and back to run, and let it pump again. Do this a few times and then try to start the engine.

If you have a 2003 Taurus with a Vulcan engine, you can check the Schrader valve on the right side of the fuel rail. The Schrader valve looks and operates like a tire valve stem, where you add air.

If you have a 2007 Taurus, you can check the Fuel Pressure Driver Module (FPDM). With the key on or while cranking, check for a duty cycle signal on the FP_M wire (DG/Y). Also, check the fuel pump ground wire BK/PK—if it's pulling down to 0.9v while cranking, this is a good sign for the FPDM.

If you have a 2000 Taurus, you likely have a variable volts pump with a FPM and sensor on the fuel rail. If the pump/filter fails to keep the desired pressure, as recorded by the sensor, you will get a code. You can also check to make sure your fuel pressure sensor vacuum hose is not broken or off.

If you are experiencing low fuel pressure, you can start by checking the brand of your fuel pump. Many aftermarket fuel pumps are complete junk. If you have a bad fuel pump, it's worth upgrading to an 18-gallon tank, if possible.

If you are experiencing a rough start after the car has been sitting for about 30 minutes, you may have a leaking fuel injector. You can pressure test on leak down of pressure to confirm this.

Finally, if you are experiencing a sharp surge while driving, from idle through the power band, you may have a weak fuel pump or faulty Fuel Rail Pressure Sensor (FRPS). You can try cleaning the FRPS before replacing it.

Frequently asked questions