Installing A Fuel Pressure Regulator On Your Sr20det Engine

Installing a fuel pressure regulator on an SR20DET engine can be a straightforward process, but it's important to take safety precautions when working with any part of the fuel system. It's recommended to have a fire extinguisher on hand. Before beginning, make sure you have suitable fuel line to connect your FPR and, if needed, an adapter and o-ring.

The first step is to purge your fuel lines. Locate the fuel pump fuse and, with the car running, pull it. The car will die, and the fuel lines will drain. Disconnect the negative battery terminal and loosen the hose clamp to remove the fuel return line and vacuum line. Remove the stock FPR, being cautious not to strip the screws.

Next, attach the fuel return line and vacuum line to the new FPR. If needed, adjust the angle of the return line tube to clear the valve cover. Lubricate the o-ring on the new FPR and wiggle it into place, replacing the screws that hold it. Double-check your connections, replace the fuel pump fuse, and reconnect the battery.

Turn the key to the accessory position to activate the fuel pump and pressurize the lines. Check for leaks and, if everything looks good, check the fuel pressure gauge. Adjust the pressure screw to reach the desired psi (typically around 3 bar or 36-44 psi). Once adjusted, start the car and re-check the gauge.

Disconnect the negative battery terminal

Disconnecting the negative battery terminal is an important step when working on any part of your fuel system. Before you start, make sure you have a fire extinguisher nearby as a safety precaution.

To disconnect the negative battery terminal, first locate the battery under the hood of your car. The battery will be a rectangular unit with two terminals on top—a positive (+) terminal and a negative (-) terminal. The negative terminal will have a black cable attached to it, while the positive terminal will have a red cable.

Once you've located the battery and identified the negative terminal, you can proceed to disconnect it. Make sure the car is turned off and the engine is cool before beginning. Use a wrench or socket to loosen the nut that secures the negative battery cable to the terminal. Be careful not to touch any other parts of the car with the wrench or socket, as this could result in an accidental short circuit.

After loosening the nut, carefully remove the cable from the terminal. You may need to wiggle it gently to detach it completely. Be cautious not to let the cable touch any metal parts of the car, as this could cause a short circuit. Once the cable is disconnected, move it away from the battery to avoid accidental contact.

At this point, you can continue with your fuel pressure regulator installation, safe in the knowledge that the electrical system is now deactivated. Remember to reconnect the negative battery terminal once you've completed your work. To do so, simply reattach the cable to the negative terminal and tighten the nut securely.

Remove the stock FPR

To remove the stock FPR, start by purging your fuel lines. Locate the fuel pump fuse in the panel under your steering wheel and, with the car running, pull the fuse. After a few seconds, the car will die and the lines will be drained of fuel. Next, disconnect the negative battery terminal.

Now, locate the stock FPR. It is on the driver's side of the fuel rail, between the valve cover and the intake manifold, and is held in place with two Phillips head screws. Apply some PB Blaster and use a large flathead screwdriver and a hammer to gently tap the screws out. Be careful not to strip the screws. Once the screws are out, wiggle the FPR out of the fuel rail, using a shop towel to catch any leftover fuel.

Loosen the hose clamp and remove the fuel return line, then remove the vacuum line. Your stock FPR can now be removed.

Install the new FPR

To install the new FPR, you will need to start by purging your fuel lines. Locate the fuel pump fuse in the panel under your steering wheel and, with the car running, pull the fuse. After a few seconds, the car will die and the fuel lines will be drained. Disconnect your negative battery terminal and loosen the hose clamp before removing the fuel return line and the vacuum line.

Now, you can remove the stock FPR. To install the new one, lubricate the o-ring on the new FPR with motor oil and attach the fuel return line, tightening down the hose clamp. Attach the vacuum line, and wiggle the FPR into place. Replace the screws that hold the FPR in place, double-check your connections, and replace the fuel pump fuse and reconnect your battery.

Turn the key to the accessory position without starting the car to activate the fuel pump and pressurize the lines. Check for leaks and, if your connections look good, check the fuel pressure gauge. If it's over 50psi, you'll need to use a 10mm wrench to adjust the pressure screw at the top. Clockwise increases the pressure, and counter-clockwise decreases it. Once you have your FPR adjusted properly, start the car and check the gauge again. Finally, spin the retainer nut down to the head of the FPR to protect your adjustment screw.

Reattach the fuel return line and vacuum line

Once you have installed the new fuel pressure regulator, you will need to reattach the fuel return line and the vacuum line.

First, loosen the hose clamp and reattach the fuel return line. Then, attach the vacuum line. You may need to use a longer vacuum line and coil it around to prevent any kinks.

Now, wiggle the FPR into place. You may need to remove the intake manifold support bracket to fit the FPR in. Once it is in place, replace the screws that hold the FPR in place. Be cautious not to damage the screw heads.

Finally, double-check your connections. If all looks well, replace the fuel pump fuse and reconnect your battery. Turn the key to the accessory position without starting the car to activate the fuel pump and pressurize the lines. Check for leaks first. If your connections look good, check the fuel pressure gauge.

Adjust the fuel pressure

Adjusting the fuel pressure on your SR20DET is a delicate process that requires careful attention to safety and detail. Here is a step-by-step guide on how to adjust the fuel pressure:

• Safety First: Before you begin, ensure that you have a fire extinguisher nearby whenever you are working on any part of your fuel system. It is also crucial to disconnect the negative battery terminal to eliminate any electrical power while you work with the fuel system.
• Accessing the Fuel Pressure Regulator: The fuel pressure regulator on the SR20DET is located on the driver's side of the fuel rail, nestled between the valve cover and the intake manifold. To access it, you will need to remove the intake manifold support bracket temporarily.
• Adjusting the Fuel Pressure: With your regulator accessible, use a 10mm wrench to adjust the pressure screw at the top. Turning the screw clockwise will increase the fuel pressure, while counter-clockwise turns decrease it.
• Prime the Fuel Pump: During the adjustment process, you may need to "re-prime" the fuel pump by switching the key off and back on without starting the car. This will help maintain consistent fuel pressure as you fine-tune the setting.
• Checking Fuel Pressure: After adjusting the pressure, reconnect the battery and turn the key to the accessory position to activate the fuel pump and pressurize the lines without starting the engine. This step is crucial, as it allows you to safely check the fuel pressure gauge and make adjustments without the engine running.
• Fine-Tuning: Once you have set the desired fuel pressure, start the car and re-check the gauge to ensure that the pressure remains at your desired setting. Make any final adjustments as needed.
• Securing the Adjustment: Finally, tighten the retainer nut down to the head of the FPR to protect your adjustment screw from unintentional movement. Reinstall the intake manifold bracket, and you're done!

It is worth noting that there are different opinions on whether to adjust the fuel pressure with the engine running or turned off. Some people suggest priming the rail and checking the gauge with the car turned on but not started, while others recommend doing so with the engine idling. It is generally recommended to avoid running the engine at high RPMs during the adjustment process, as this can cause excessive fuel pressure and potential damage.

Frequently asked questions