Leaking fuel pressure regulator

Fuel from the pressure regulator can't enter the intake manifold with out passing through the injector first. That means that if you have a leak in the inlet manifold you have a leaking injector.
A fuel pressure regulator is no more than a controlled leak. You test pressure on the fuel rail, if you have pressure you have fuel to the injectors.
The regulator controls that pressure by controlling the return flow to the fuel tank. You are in trouble when a pressure regulator does not flow (leak) fuel from the pressure (fuel rail) and return ports.
To test weather a injector is leaking you remove it from the inlet manifold and pressurize the injector.

Hi Raquel,here's a link to your fuel pressure regulator and how to replace. Repair Guides Gasoline Fuel Injection Fuel Pressure Regulator AutoZone com Here's a new pressure regulator. GP Sorensen Fuel Pressure Regulator 800 366 at AutoZone com

i would check the fuel pressure. see how fast the pressure goes down. most cars i have worked on it dosnt take that many key-ons to get fuel. a fuel pressure regulator could be leaking. there is a check ball in the pump to keep the fuel from draining back. since the pump is new, i would check the regulator and poss. the injectors. its poss. for an injector to leak or stick open

Not sure why Haynes says to do that. below is instructions from autozone.com, and none of the engines require the fuel rail to come off. That said, if you have the 3.4, you may need to pull the upper intake manifold.

Removal & Installation The need to work as cleanly as possible cannot be over-emphasized. Even the smallest amount of dirt, if allowed into the fuel pressure regulator and/or the fuel rail, will find its way to the fuel injectors. The nozzle openings of the injectors are very small. Keep hands and tools clean. Clean the areas to be disconnected with a suitable solvent. Carefully cover open fittings and connections to keep out foreign material. Dirt in the injectors almost guarantees a clogged fuel injector and engine performance problems.

3.4L (VIN E) Engines

1. Disconnect the negative battery cable.
2. Relieve the fuel system pressure.
3. Remove the upper intake manifold assembly.
4. Disconnect the vacuum line from the pressure regulator.
5. Remove the regulator retaining screw and remove the retainer bracket. Using a clean shop cloth to catch fuel spillage, carefully pull the regulator from the fuel rail. Twist the regulator slightly while removing to ease removal. Discard the O-ring.
   
   

   Fig. Exploded view of the fuel pressure regulator mounting-3.4L (VIN E) engines
   

To install:

1. Clean all parts well. DO NOT use shop compressed air to test or clean a fuel pressure regulator. Clean the fuel pressure regulator screen, if necessary. DO NOT immerse the fuel pressure regulator in a solvent bath or it will be damaged.
2. If the filter screen has been contaminated, it should be removed and the pressure regulator replaced.
3. Lubricate a new pressure regulator O-ring with clean engine oil and install on the regulator inlet.
4. Install the fuel return pipe to the regulator.
5. Install a new retainer and spacer bracket into the slot on the fuel rail and install the pressure regulator to the fuel rail. Tighten the fuel return line nut to 13 ft. lbs. (17 Nm).
6. Connect the vacuum line to the pressure regulator and install the retainer screw. Tighten to 76 inch lbs. (8.5 Nm).
7. Inspect and verify that the retainer and spacer bracket is engaged in the slots in the fuel rail. Grasp and pull on the regulator to ensure that it is properly seated.
8. Install the upper intake manifold.
9. Connect the negative battery cable.
10. Inspect for leaks using the following procedure:
    1. Turn the ignition switch to the ON position for 2 seconds.
    2. Turn the ignition switch to the OFF position for 10 seconds.
    3. Turn the ignition switch to the ON position again.
    4. Inspect all areas for fuel leaks.

3.8L Engines

1. Disconnect the negative battery cable.
2. Relieve the fuel system pressure.
3. Clean any dirt from the fuel pressure regulator retaining ring.
4. Remove the vacuum hose from the pressure regulator.
5. Remove the snaprings. Twist the regulator slightly and pull the pressure regulator from the fuel rail. Use a shop towel to catch fuel spillage as the regulator is removed.
6. Remove the O-rings and O-ring back-up.

To install:

1. Clean all parts well. DO NOT use shop compressed air to test or clean a fuel pressure regulator. Clean the fuel pressure regulator screen, if necessary. DO NOT immerse the fuel pressure regulator in a solvent bath or it will be damaged.
2. If the filter screen has been contaminated, it should be removed and the pressure regulator replaced.
3. Lubricate the new pressure regulator O-rings with clean engine oil. Install the O-ring back-up, the large O-ring and then the small O-ring. Install the pressure regulator and secure with the snapring.
4. Attach the vacuum hose.
5. Connect the negative battery cable.
6. Inspect for leaks using the following procedure:
   1. Turn the ignition switch to the ON position for 2 seconds.
   2. Turn the ignition switch to the OFF position for 10 seconds.
   3. Turn the ignition switch to the ON position again.
   4. Inspect all areas for fuel leaks.
   
   

1. Disconnect the negative battery cable.
2. Relieve the fuel system pressure.
3. Clean any dirt from the fuel pressure regulator retaining ring.
4. Remove the vacuum hose from the pressure regulator.
5. Remove the snaprings. Twist the regulator slightly and pull the pressure regulator from the fuel rail. Use a shop towel to catch fuel spillage as the regulator is removed.
6. Remove the O-rings and O-ring back-up.

To install:

1. Clean all parts well. DO NOT use shop compressed air to test or clean a fuel pressure regulator. Clean the fuel pressure regulator screen, if necessary. DO NOT immerse the fuel pressure regulator in a solvent bath or it will be damaged.
2. If the filter screen has been contaminated, it should be removed and the pressure regulator replaced.
3. Lubricate the new pressure regulator O-rings with clean engine oil. Install the O-ring back-up, the large O-ring and then the small O-ring. Install the pressure regulator and secure with the snapring.
4. Attach the vacuum hose.
5. Connect the negative battery cable.
6. Inspect for leaks using the following procedure:
   1. Turn the ignition switch to the ON position for 2 seconds.
   2. Turn the ignition switch to the OFF position for 10 seconds.
   3. Turn the ignition switch to the ON position again.
   4. Inspect all areas for fuel leaks.

1994 Chevrolet S10 Blazer 4.3L, Vin W Customer Concern: DTC 45 The spark plugs are black on both banks. Right bank plugs are damp. Removed the tuning valve and looked inside the plenum. Can see a washed/clean area on the right side. Fuel pressure is good, it holds when the pump stops. Tests/Procedures: 1. Remove the upper intake plenum cover and inspect for a fuel leak at the fuel pressure regulator.

2. Inspect the fuel pressure regulator and return lines and fittings at the left side of the plenum.

3 Replace the Central Multipoint Fuel Injection (CMFI) unit. Potential Causes: Leaking Fuel Line - One or more may have a problem.
Leaking Fuel Pressure Regulator
Tech Tips: The fuel pressure regulator may only leak at a cold or hot engine, only with vacuum applied, or only without vacuum applied. The leaking at the fuel lines and fittings have as often been the result of repairs as the initial cause of the problem. Handle the lines and fittings carefully. The fuel pressure regulator is a integral part of the Central Multi-port Fuel Injection (CMFI) unit. Any failure requires entire unit replacement.

Replacing the fuel pressure regulator, involves just replacing the regulator at the end of the fuel rail in the engine compartment, but fuel pressure sensor - does this mini-van have a fuel pressure sensor?
replacing the fuel pressure regulator: (1) locate it at the end of the fuel rail in the engine compartment,
(2) relieve fuel system pressure (3) disconnect fuel pressure regulator vacuum line. (4) remove fuel pressure regulator retaining screw (retain for re-use (5) using a shop towel to catch spilled fuel, lift & twist Fuel pressure regulator to remove it from the fuel rail. (6) remove/discard retainer and spacer bracket from the fuel rail. (7) remove fuel pressure regulator from the engine fuel return pipe. (8) remove/discard Fuel Pressure Regulator inlet O-ring (9) Check Fuel Pressure Regulator filter screen for contamination - if contaminated, replace Fuel Pressure Regulator. (10) Lubricate new Fuel Pressure Regulator inlet O-ring with clean engine oil & install onto the Fuel Pressure Regulator inlet. (11) Install the fuel return pipe onto the Fuel Pressure regulator (12) Install new retainer & spacer bracket into the slot on the fuel rail.
(13) Install Fuel Pressure Regulator onto Fuel Rail & tighten Engine Fuel Return Pipe nut to 13 ft-lbs (17 Nm). (14) connect Fuel Pressure Regulator vacuum line, (15) Install Fuel Pressure Regulator attachng screw & tighten to 76 in-lbs (8.5 Nm). (16) Inspect & verify that retainer & spacer bracket is engaged in the slots on the fuel rail. Grasp & pull on the Fuel Pressure Regulator.
to ensure that the Fuel Pressure Regulator is properly seated. (17) inspect for fuel leaks with this
procedure: On 2sec,(holy rollers), off 10sec will be left on, inspect for leaks while running.

usually caused by busted diaphram in fuel pressure regulator allowing fuel to be drawn thru regulator directly to intake manifold. Pull vacuum line off regulator, plug line with golf tee, start car and watch to see if gas comes out of regulator. If yes, turn off car, replace regulator. The regulator sits near the fuel rail on the top of the engine as shown below. I will paste replacement instructions below from autozone.com in case you need to replace the regulator. Please let me know if you have any questions.

Removal & Installation

4.2L Engine

1. Relieve the fuel system pressure.
2. Remove the air cleaner outlet resonator.
3. Disconnect the engine wiring harness from the retaining clips at the front of the engine.
4. Disconnect the fuel pressure regulator vacuum line.
5. Clean any dirt from the fuel pressure regulator and the surrounding area.
6. Disconnect the fuel return pipe.
7. Remove the fuel return pipe retainer.
8. Remove the fuel pressure regulator retainer.
9. Remove the fuel pressure regulator.
10. Inspect the regulator filter screen for contamination. If contaminated, replace the fuel pressure regulator.

To install:

1. Install the regulator filter.
2. Install the new O-ring on the fuel pressure regulator.
3. Lubricate the fuel pressure regulator O-ring with clean engine oil.
4. Push the fuel pressure regulator into the regulator housing on the fuel rail.
5. Install the fuel pressure regulator retainer. Tighten the regulator retainer screw to 71 inch lbs. (8 Nm).
6. Install the fuel return pipe retainer. Tighten the return pipe retainer screw to 71 inch lbs. (8 Nm).
7. Connect the fuel return pipe.
8. Connect the fuel pressure regulator vacuum line.
9. Connect the negative battery cable.
10. Inspect for leaks:
    1. Turn ON the ignition for 2 seconds.
    2. Turn OFF the ignition for 10 seconds.
    3. Turn ON the ignition.
    4. Inspect for fuel leaks.
    
    
11. Install the engine wiring harness into the retaining clips at the front of the engine.
12. Install the air intake resonator.

You could have either an injector that is stuck open or a fuel pressure regulator that has developed a leak. A leaky injector will usually only leak fuel into one cylinder as it is located just above the intake valve in the lower part of the intake while a leaky fuel pressure regulator will leak fuel into the front end of the intake manifold [behind the throttle plates] and the fuel will acuumulate throughout the upper intake plenum. When a fuel pressure regulator develops a leak the fuel that is escaping from it flows through the small 1/8" diameter plastic vacuum line which goes from the top of the regulator to the intake manifold. Even a trace of fuel in this line means the regulator is bad. I've seen both leak items leak but probably replace 10 regulators leak for every one injector. Good luck, hope you find your problem!

For 2000 Chevrolet Truck Blazer 4WD 4.3L SFI 6cyl
If your engine is a 4.3L V-6 with CPI (central point injection) it is inside the upper intake manifold. The upper intake manifold is bolted on top of the normal intake manifold.

The throttle body is mounted on it and your fuel lines terminate into the center of this.


Removal & Installation

1. Relieve the fuel system pressure.
2. Remove the air cleaner outlet resonator.
3. Disconnect the engine wiring harness from the retaining clips at the front of the engine.
4. Disconnect the fuel pressure regulator vacuum line.
5. Clean any dirt from the fuel pressure regulator and the surrounding area.
6. Disconnect the fuel return pipe.
7. Remove the fuel return pipe retainer.
8. Remove the fuel pressure regulator retainer.
9. Remove the fuel pressure regulator.
10. Inspect the regulator filter screen for contamination. If contaminated, replace the fuel pressure regulator.

To install:



Fig. Fuel pressure regulator-4.2L engine

1. Install the regulator filter.
2. Install the new O-ring on the fuel pressure regulator.
3. Lubricate the fuel pressure regulator O-ring with clean engine oil.
4. Push the fuel pressure regulator into the regulator housing on the fuel rail.
5. Install the fuel pressure regulator retainer. Tighten the regulator retainer screw to 71 inch lbs. (8 Nm).
6. Install the fuel return pipe retainer. Tighten the return pipe retainer screw to 71 inch lbs. (8 Nm).
7. Connect the fuel return pipe.
8. Connect the fuel pressure regulator vacuum line.
9. Connect the negative battery cable.
10. Inspect for leaks:
    1. Turn ON the ignition for 2 seconds.
    2. Turn OFF the ignition for 10 seconds.
    3. Turn ON the ignition.
    4. Inspect for fuel leaks.
11. Install the engine wiring harness into the retaining clips at the front of the engine.
12. Install the air intake resonator.

Hope help with this (remember rated this post).

REPLACE FUEL PRESSURE REGULATOR AND ALL O-RINGS ON FUEL RAIL.REPLACE THE ENTIRE FUEL RAIL AND FUEL PRESSURE REGULATOR.IF FUEL RAIL IS LEAKING..