93-94 Fuel Pressure Regulator Replacement

[Vince P]

Fuel Pressure Regulator Replacement

1993 –94 Northstar

Share the knowledge –I have had some requests and questions about this process, which is the reason that I put this process together.

Pre-removal notes

1. Remove the air cleaner, PCV tubing connection and the air duct to the throttle body. This gives easy access to the fuel injector cable and easier access to the pressure bleed valve for the fuel line.

2. There will be some fuel spilling to the bottom of the intake manifold as you raise the fuel rail. I sucked this out with a turkey baster and piece of tubing.

3. You will need a torque wrench. The torque on the intake manifold cover bolts is 102 inch-pounds or 11.5 nt-meters.

4. Remove the spark plug wires channel bottom cover (curved piece). Then raise the plastic channel holding the spark wires off the intake manifold. Push it back for access to 2 cover bolts.

5. The manual says to disconnect the negative terminal on the battery and disconnect the fuel injector cable (The connector is laying on top of the Transmission in my car. There must be some safety reason for these requirements. I did not do either.

6. The fuel injector cable is incased in a corrugated plastic black cover.

Removal

1. Bleed the fuel pressure at the tire type valve. This is to the right (rear of the car) of the throttle body. It has a cap that should be removed. Lay out a rag to catch the gas that will come out. Take the wet rag outside. Reinstall the cap.

2. There are 12 bolts that hold the intake manifold cover that must be removed. Start by turning each one a half turn so not to torque the cover.

3. Remove the cover.

4. On the bottom (outside) of the manifold, the wiring harness is held in place by a tie wrap. If you cut this tie wrap, you will be able to raise the gasket and attached assemblies 6 inches (more than enough clearance).

5. What you are looking at is the gasket. On it is mounted the fuel injector wiring harness, the fuel injectors and connections, the MAP Sensor and the IAT sensor. On the left side (driver side) towards the rear is the Fuel Pressure Regulator. In front of that is the wiring connection. In the front corner is the connection to the fuel inlet from the tank.

Note that the Fuel pressure regulator and the fuel inlet (fuel rail) are pushed into tubes on the bottom of the intake manifold. These are sealed with “O rings”. These were binding and difficult to remove. There is a possibility that you will destroy the gasket. This is a major part.

Note: The fuel pressure regulator does not have any hose connected to it. It uses the vacuum within the intake manifold. I put a small piece of hose on the fitting to help wiggle the fuel pressure regulator out off the fuel return tube.

Note: there are not clips or any other of locks holding anything. The “O rings” (3) are the only thing that holds every thing in place.

6. Wiggle, shake prod, the gasket in the area of the fuel pressure regulator and left front cover. I had to use a broad screwdriver, which I was able to put under the fuel rail gasket mount at the fuel inlet connection. Eventually, the two “O rings will give. The “O ring” holding the wiring seal comes out easily.

7. Raise the gasket and pull off the fuel rail going into the side of the fuel pressure regulator.

8. The gasket has three plastic fingers that hold the fuel pressure regulator in place. Pop it out of the fingers.

9. I reused all the “O rings”, except the one in the center of the fuel pressure regulator. There was a new “O ring” with the regulator.

10. At this point I cleaned the gasket and mating surfaces (including the area around the wiring harness seal).

11. Put grease, on the “O rings” and the fuel lines. Grease the “O ring” on the fuel injector cable seal. Every thing will pop back in, with ease. Make sure the fuel pressure regulator is under the plastic fingers.

12. Look at each fuel injector. They should be in place. Note that the bottom of the fuel injectors Do NOT has “O rings”. They have a strange seal that is held in place by the pressure of the top cover.

13. Test the system for leaks. Turn on the ignition. Note the fuel pump will only go on for 2 or 3 seconds (This is part of a safety system). Turn on the ignition 3 or 4 times. This will bleed the air out of the system. The system is should now be pressurized. Turn the ignition off. CHECK FOR FUEL LEAKS. The bottom of the manifold should be dry.

14. Install a new tie wrap on the fuel injector cable

15. Torque the top cover in steps. See torque spec above. There is a specific sequence for torquing, which is a little bit strange.

Torque sequence – Looking on top of the cover from the front of the car

10------5----12----7----2--------9

3--------8----1-----6----11------4

Note: Good time to clean the throttle valve

16. Install the air cleaner, and associated parts.

17. Snap in the spark plug channel parts.

Check the area, then start the engine.

At this point I used a hose to hear if there is any air leaking around the cover and the fuel injector cable.

Vince P

[jfreezn]

Thanks for the great detail Vince. I know my 94 will need a regulator before too long and you have saved me the time to scope the job out.

Jim