Returned the FPR to the parts store, bad idea,

[The Fred]

Well I was out of money and broke so I thought,

Heck,

If I return the FPR I can go and get some good gas and try that in there.. but it didn't work out.

Still doing the same thing (Refer to http://caddyinfo.ipbhost.com/index.php?sho...=10479&st=0 ) so now I guess I will have to replace the FPR

I noticed that the FPR they gave me had a nipple like thing on it that a hose would go on.. so is it possible that it might be one of the easier ones to replace? I'm going to borrow some torx wrenches tomorrow...

[Cadillac Jim]

The thing about the FPR is that it is part of the original Bosch fuel injection and is an all-mechanical part, operating with fuel pressure and vacuum. None of the OBD II electrical sensors will direclty detect minor malfunctions of the FPR, like leakage of gasoline through the diaphram into the vaccum system or intake manifold. That will cause slow starting in a hot engine and can cause the engine to tend to the rich side, with a slight loss of gas mileage, and you won't get a code.

The nipple with the o-ring goes straight down into the fuel rail. There is a small pipe out the side of the big end; a hose goes on that. There is a small plastic filter on the small end. They are all easy to replace. I did mine in five minutes. The key is to have all the tools on-hand. A real time-saver is a mechanic's pick or a crochet needle to get out the old small plastic filter and the old o-ring. You will probably re-use the existing retainer clip and not use either of the retainer clips packaged with the part.

My detailed post on how to change the FPR on a steel fuel rail is here. If you need a picture I will pop my beauty cover and take one.

[The Fred]

Will a bad FPR cause the problems I'm having?

Vincent P sent me this...

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

Yours looks the same

Except for there seem to be different types of FPR gadgets

Loosen the gas cap to relieve pressure in the fuel tank. This will keep you from getting a gasoline facial when you pull out the old FPR.

Remove the "beauty cover" (actually it's a heat shield and soundproofing and very important).

Put a shop rag or paper towel under the fuel rail relief valve on the front driver's side and "let the air out of the tire" to bleed the pressure down. It should be just a few drops.

Look on the driver's side rear of the fuel rail and you will see the FPR. If you have one in your pocket you will recognize the old one easily.

Carefully pull the vacuum hose off the FPR.

If you have a metal fuel rail, use the needle-nose to pull the retaining clip out of the slot. Be careful; you will re-use this clip.

Pull the FPR straight out. A quarter-shaped plastic filter and a small o-ring will remain. Use your mechanic's hook or your wife's crochet needle to pick these out. This is the hardest part of the job.

Place the new FPR in the fuel rail receptacle. Be careful to align the vacuum hose fitting at the same angle as the old one.

Press the FPR in and re-insert the retaining clip. Some cars may need one of the two retaining clips that come with the new FPR (NOT the C-clip); I have the steel fuel rail and needed to re-use the existing retainer clip.

Put the vacuum hose onto the new FPR.

Put the beauty cover back on.

Tighten the gas cap.

Close the hood and start the car. If it's still flooded, hold the throttle wide open and crank for a few seconds (the PCM will cut off the injectors with WOT and less than 1,000 rpm, just to allow you to clear a flooded engine), then start normally.

[JasonA]

The primarly symptoms of a bad FPR are hard starting...and/or poor driveability. Vague, I know. The procedure on a 1994 and older Norsthar is different from a 1995 and later one. The procedures for the 1993-1994 engines is numbers 1-17 above. The last set of directions are for the 1995 and later engines.

[The Fred]

The primarly symptoms of a bad FPR are hard starting...and/or poor driveability. Vague, I know. The procedure on a 1994 and older Norsthar is different from a 1995 and later one. The procedures for the 1993-1994 engines is numbers 1-17 above. The last set of directions are for the 1995 and later engines.

Thanks,

That's what I thought.

It sure was good of VP to e-mail that to me