Fuel Pressure Regulator: Service and Repair

Fuel Pressure Regulator Valve N276

The fuel pressure regulator valve is located inside the fuel rail. The valve maintains a constant pressure in the rail and in the high pressure lines.

The regulator valve opens when the pressure in the high side circuit is too high. Some of the fuel flows from the rail back into the fuel tank via a return line.

If the pressure in the high side is too low, the pressure regulator valve closes. By doing this, the valve seals off the high pressure side from the low pressure side.


Follow the guidelines when working on the fuel system. Refer to => [ Safety Precautions ] Safety Precautions.

Follow the guidelines for clean working conditions. Refer to => [ Clean Working Conditions ] Clean Working Conditions.

Always follow these instructions before and during work.

- Remove the engine cover. Refer to => [ Engine Cover ] Engine Cover.

- Clean the threaded area around the regulator valve with, for example, a commercially available detergent, before removing. Dirt must never get into the hole in the fuel rail.

• Clean carefully, the cleaner must not enter the connector.

• The fuel pressure regulator valve cannot be used again.

- Dry the fuel pressure regulator valve.

- Disconnect the connector from the fuel pressure regulator valve.

- Counter hold at the housing hex and loosen the union nut. Then remove it by hand.

- Suction any dirt out of the hole in the fuel rail, the threads and the sealing surface. Do not use mechanical tools.

• Seal the hole in the fuel rail with a plug to prevent dirt from entering.

Installing

• Check the fuel pressure regulator valve sealing surface and threads for damage.

• Check the sealing surface on the bore in the fuel rail.

• The threads on the fuel pressure regulator valve must be free of oil and grease.

- Tighten the union nut by hand.

- Align the fuel pressure regulator valve so the wire is not taut after connecting the connector.

- Counter hold at the housing hex and tighten the union nut. Tightening specification, see - item 6 - in the => [ Fuel System Component Overview ] Fuel System Component Overview.

- After installing, allow the engine to run at a moderate speed for a few minutes and then turn it off.

- Check the fuel system for leaks.

- Check the Diagnostic Trouble Code (DTC) memory. Refer to the vehicle diagnostic tester.

- Perform a road test fully pressing the accelerator pedal at least one time. Then, check the high pressure area for leaks again.

- Check the DTC memory one more time, refer to the vehicle diagnostic tester.