Fuel Pressure Regulator: Service and Repair

Fuel Pressure Regulator Replacement

Removal Procedure




1. Remove the generator. Refer to Generator Replacement (V6) (Service and Repair)Generator Replacement (V8) (Service and Repair)Generator Replacement (6.6L) (Service and Repair).
2. Remove the intake manifold tube. Refer to Intake Manifold Tube Replacement (Intake Manifold Tube Replacement).
3. Remove the water outlet tube. Refer to Water Outlet Tube Replacement (LU3) (Service and Repair)Water Outlet Tube Replacement (LMM) (Service and Repair).
4. Unbolt and reposition the air conditioning (A/C) compressor (with the hoses attached) to the right side of the engine compartment. Refer to Air Conditioning Compressor Replacement (LLY/LMM) (Removal and Replacement)Air Conditioning Compressor Replacement (LU3) (Removal and Replacement)Air Conditioning Compressor Replacement (LY2, LY5, LH6, L76, L92 and LMG) (Removal and Replacement)Air Conditioning Compressor Replacement (HP2) (Removal and Replacement).
5. Disconnect the engine coolant temperature (ECT) sensor electrical connectors (1) and reposition the harness branches.




6. Disconnect the wiring harness extension electrical connector (1) from the fuel pressure regulator.




7. Reposition the fuel hose clamp (2) at the fuel injection fuel feed manifold.




8. Reposition the fuel hose clamp (3) at the fuel injection pump.
9. Remove the fuel hose (4) from the fuel injection fuel feed manifold and injection pump.




10. Clean the fuel pressure regulator and high pressure injection pump thoroughly with solvent, such as GM P/N 12377981 (Canadian P/N 10953463) or equivalent.
11. Using compressed air, thoroughly blow dry the regulator and pump.
12. Remove the 3 fuel pressure regulator screws (1) using a T25 TORX(R).
13. Remove the fuel pressure regulator (2).
14. If dirt or debris is found in the bore or seating surfaces of the fuel injection pump, perform the following:

* Place a clean rag over the bore on order to collect the excess fuel.
* Bump the engine over in order to flush any debris out of the regulator bore.

Installation Procedure

Note: If the pressure regulator is being re-used, check the O-rings for damage. If the O-rings are damaged, install NEW O-rings.




1. Lubricate and install NEW O-rings onto the regulator. Lubricate the O-rings with clean, NEW engine oil.

Note: If the regulator is installed at an angle the O-rings may be damaged, resulting in possible fuel leakage.

2. Install the fuel pressure regulator (2).

Caution: Refer to Fastener Caution (Fastener Caution).

3. Install the 3 fuel pressure regulator screws (1) using a T25 TORX(R).

* Tighten the screws a first pass to 4 Nm (35 lb in).
* Tighten the screws a final pass to 7 Nm (62 lb in).




4. Install the fuel hose (4) to the fuel injection fuel feed manifold and injection pump.
5. Position the fuel hose clamp (3) at the fuel injection pump.




6. Position the fuel hose clamp (2) at the fuel injection fuel feed manifold.




7. Connect the wiring harness extension electrical connector (1) to the fuel pressure regulator.




8. Position the engine wiring harness branches to the ECT sensors and connect the ECT sensor electrical connectors (1).
9. Position and install the A/C compressor. Refer to Air Conditioning Compressor Replacement (LLY/LMM) (Removal and Replacement)Air Conditioning Compressor Replacement (LU3) (Removal and Replacement)Air Conditioning Compressor Replacement (LY2, LY5, LH6, L76, L92 and LMG) (Removal and Replacement)Air Conditioning Compressor Replacement (HP2) (Removal and Replacement).
10. Install the water outlet tube. Refer to Water Outlet Tube Replacement (LU3) (Service and Repair)Water Outlet Tube Replacement (LMM) (Service and Repair).
11. Install the intake manifold tube. Refer to Intake Manifold Tube Replacement (Intake Manifold Tube Replacement).
12. Install the generator. Refer to Generator Replacement (V6) (Service and Repair)Generator Replacement (V8) (Service and Repair)Generator Replacement (6.6L) (Service and Repair).
13. Prime the fuel system. Refer to Fuel System Priming (Fuel System Priming).
14. Start the engine. If the engine stalls, repeat the above step.
15. Once the engine starts, inspect for fuel leaks.