How to Replace a Fuel Pressure Regulator in Vehicles

by Contributing Writer; Updated June 12, 2017

The fuel pressure regulator in your Vehicles is used to help keep the fuel system's pressure constant. If the regulator is bad, the result is often low pressure in the system. Symptoms can include a rough, sputtering engine, failing to start after ignition and worse fuel mileage. Replacing a fuel pressure regulator, like any fuel system component, can be a dangerous task because of the pressure within the system.

Under The Hood:

 How to Replace a Fuel Pressure Regulator in a 2000 Chevrolet Malibu 3.1 Liter

Open the hood on the Malibu. Disconnect the negative battery cable from the battery. Locate the fuel pressure testing port on the top of the fuel rail and remove the small cap from the top of the port. Wrap a screwdriver tip in a towel. Insert the screwdriver tip into the port. Depress the pin in the center of the pressure testing port slightly to relieve the fuel pressure in the fuel lines. Allow the rag to absorb the fuel. Install the cap back onto the fuel pressure testing port.

Remove the fuel pressure regulator vacuum hose from the top of the fuel pressure regulator, which is located at the end of the fuel rail. Hold a rag beneath the regulator assembly to catch fuel that spills. Remove the mounting screw from the pressure regulator, using a Torx bit hand driver. Disconnect the fuel return line bottom of the fuel pressure regulator. Use an open-end wrench to remove the line from the bottom of the regulator.

Remove the old spacer and fuel pressure regulator retainer from the fuel rail, using pliers if needed. Install a new spacer and retainer onto the fuel rail.

Insert the return line onto the new pressure regulator and tighten the nut, using your open end wrench. It is important to install the line first, as twisting the fuel pressure regulator during installation can damage the regulator. Tighten the fuel return line nut to 13 foot-pounds, using a crowfoot attachment and a torque wrench. Install a new retainer and spacer onto the fuel rail, by hand. Install the fuel pressure regulator onto the fuel rail and tighten the screw to 76 inch-pounds, with a torque wrench and Torx bit socket. Reconnect the negative battery terminal.

Sit in the driver's seat. Turn the ignition key to the "Accessories" position without starting the engine. Turn the ignition key back to the "Off" position. Repeat this on and off process three times to completely pressurize the fuel lines and system. Turn the engine on and step out of the car. Inspect your work area near the fuel pressure regulator and underneath the vehicle for leaks. If a leak is spotted, turn the vehicle off immediately, locate the source and repair the leak.

Items you will need

  • Torx bit hand driver set

  • Open-end wrench set

  • Aerosol engine parts cleaner

  • 2 rags

  • New fuel pressure regulator

  • New spacer and regulator bracket

  • 1/2-inch torque wrench

  • 1/2-inch open-end ratchet adapters

  • 3/8-inch torque wrench

  • 3/8-inch Torx bit socket set

 How to Replace a Fuel Pressure Regulator on a Chevy Blazer

Relieve the vehicle's fuel system pressure by removing the fuel cap on the side and the fuel pump relay inside the fuse box, then run the engine until it stalls and continue cranking it for five to 10 seconds.

Disconnect the battery's negative cable once the pressure is relieved.

Remove the air intake resonator by disconnecting all connectors, ducts and lines connected to it--the ducts have hose clamps that need loosening--removing the resonator's mounting bolts with a wrench and detaching the ventilation hose from the valve cover.

Clean away all dirt and debris that is around the pressure regulator and fuel lines to prevent anything from entering the fuel system. Wipe it away with a clean cloth. If you use acetone, water or any other liquid cleaner, make sure you completely dry the area off.

Disconnect the vacuum line at the pressure regulator, the wiring harness at the front of the engine and the fuel return line. These should either come off easily by hand or have quick-connect fittings where you press on the tabs.

Remove the pressure regulator by removing its mounting screw; this can require a screwdriver or a hex wrench.

Make sure the replacement regulator has a new O-ring and lubricate this ring with a light coat of engine oil.

Install the fuel pressure regulator, tightening the mounting screw to 71 inch-pounds. Reconnect all other parts in reverse order of removal.

Re-pressurize the fuel system by reconnecting the fuel pump relay, turning the ignition switch to the on position for two seconds and turning it back on for five. Repeat the procedure with the switch multiple times.

Items you will need

  • Wrench

  • Screwdriver

  • Rags

  • Fuel pressure regulator

  • Engine oil

 How to Replace the Fuel Pressure Regulator on a Duramax LLY

Disconnect the air intake pipe and alternator with a socket wrench. Detach the electrical connectors for the air conditioning clutch and air conditioning cut-out switch. Remove the mounting bolts for the air conditioning compressor, and push the compressor to the right of the engine.

Lift up the latches on the connectors for the main wiring harness on the engine, and release the clip on the harness to detach the connectors. Disconnect the connector from the barometric pressure sensor. Remove the mounting bolts on the bracket for the engine wiring harness with a socket wrench, and disconnect the bracket.

Disconnect the electrical connectors from the engine coolant temperature sensor, fuel temperature sensor, oil level sensor and fuel pressure regulator. Detach the water outlet tube from the engine. Release the clamps for the distribution block hoses, and disconnect the hoses. Disconnect the retaining bolts for the Exhaust Gas Recirculation (EGR) hose, and release the clamp on the hose so you can push it aside.

Clean the fuel pressure regulator and injection pump with solvent 12377981 and compressed air. Disconnect the screws on the fuel pressure regulator with a T25 TORX tool, and detach the fuel pressure regulator.

Coat the new O-rings for the fuel pressure regulator with clean engine oil, and mount them to the new fuel pressure regulator. Install the new fuel pressure regulator, and tighten its screws to 35 inch-pounds, with a T25 TORX tool. Tighten the screws for the fuel pressure regulator again to 62 inch-pounds.

Install the remaining components by performing steps 1 through 3 in reverse order. Tighten the mounting bolts for the EGR hose and the main engine wiring harness to 15 foot-pounds with a torque wrench. Tighten the bolts for the air conditioning compressor to 37 foot-pounds.

Crank the engine until it starts to prime the fuel system. Allow the engine to idle and check for fuel leaks.

Items you will need

  • Socket wrench set

  • Solvent 12377981

  • Air compressor

  • T25 TORX tool

  • Torque wrench

About the Author

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