My 93 Pontiac GP LE 3.1 has all the symptoms of a bad fuel pressure regulator but I can't see any fuel coming out when I remove the vacuum line.

A ruptured diaphragm in the fuel pressure regulator will let extra gas enter the engine through the vacuum line to the regulator. Pull off the regulator vacuum line. Any evidence of gas? Let the engine idle a couple of minutes with the vacuum line off. If any gas starts coming out of the vacuum line nipple on the regulator, then that was the problem. Replace the fuel pressure regulator.

Very easy. Unplug the three wire connector to it, pull off the vacuum line, and dismount if from its mooring. It's on the passenger side at top of engine, back near the firewall, or on that back side of the engine.

If the FPR is bad, gas will come out of it when you remove the vacuum line. John C ... 1993 pontiac grand prix 3.1l fuel leak under throdal body

Fuel Pressure Regulator is located on the fuel rail.

1. Disconnect the negative battery cable.

2. Properly relieve the fuel system pressure.

3. Remove the air cleaner outlet tube(s).

4. Remove any necessary components to access the pressure regulator.

5. Disconnect the vacuum hose from the pressure regulator.

6. Remove the pressure regulator attaching screws.

7. Remove the pressure regulator from the fuel rail.

To Install

8. Discard the O-rings on the pressure regulator and replace them with new ones.

9. Lubricate the O-rings with clean engine oil.

10. Install the regulator into the fuel rail and tighten the retaining screws.

11. Connect the vacuum hose to the regulator.

12. Install any components removed to access the regulator.

13. Install the air cleaner outlet tube(s).

14. Connect the negative battery cable.

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.

Removal & Installation of fuel Regulators on
4.8L, 5.3L & 6.0L Engine To Remove:
CAUTION
Three styles of fuel pressure regulators and fuel rails will be used in this model year. Each regulator has a different "footprint" that consequently changes the size of the receiving port in the fuel rail. The regulator retaining clips are specific to each rail-regulator design and cannot be interchanged.

1. Remove the engine sight shield.
2. Relieve the fuel system pressure. Refer to Fuel Pressure Relief Procedure.
3. Clean the fuel pressure regulator retainer and the surrounding area.
4. Remove or disconnect the following:
   • Fuel pressure regulator vacuum line.
   • Fuel pressure regulator retainer.
   • Fuel pressure regulator.
5. Remove the following parts from the fuel rail:
   • Backup ring (10)
   • Regulator Seal O-ring (11)
   • Regulator filter (12)
   • Regulator seal O-ring (13)

To Install:

1. Make sure the NEW fuel pressure regulator retainer is the right one.
2. The tabs (1) are used on the straight vacuum port retainer (2), and the E85-straight vacuum port retainer (3).
3. The angle vacuum port retainer (4) has no tabs.
   
   
4. Install the following parts onto the fuel pressure regulator (9).
   • Backup ring (10)
   • Regulator seal O-ring (11)
   • Regulator filter (12)
   • Regulator seal O-ring (13)
5. Lubricate the fuel pressure regulator O-rings with clean oil.
6. Install the fuel pressure regulator and retainer. CAUTION
   Whenever the fuel pressure regulator is removed from the fuel rail NEW O-rings and a NEW retaining clip should be used on reinstallation.
   
7. Connect the vacuum line.
8. Tighten the fuel filler cap.
9. Use the following to inspect for leaks:
   • Turn ON the ignition, with the engine OFF, for 2 seconds.
   • Turn OFF the ignition for 10 seconds.
   • Turn ON the ignition, with the engine OFF.
   • Install the engine sight shield.

8.1L Engine To Remove:
Fuel pressure regulator vacuum line

1. Before servicing the vehicle refer to the precautions at the beginning of thjs section
2. Remove the fuel injector sight shield as needed
3. Relieve fuel system pressure (See: Fuel Pressure Relieving)
4. Disconnect the fuel pressure regulator vacuum line (A) 8.1L Fuel pressure regulator retainers
   
   
5. Clean any dirt from the fuel pressure regulator retainer and the surrounding area
6. Remove the fuel pressure regulator retainer (I)
7. Remove the fuel pressure regulator (H) from the fuel pressure regulator housing

To Install:
8.1L Fuel pressure regulator retainers

1. Install or connect the following:
   • Backup ring (J) on the fuel pressure regulator (H)
   • New large O-Ring (K) on the fuel pressure regulator
   • Regulator filter (L) on the fuel pressure regulator
   • New small O-Ring (M) on the fuel pressure regulator
2. Lubricate the fuel pressure regulator large O-Ring and the small O-Ring with clean engine oil
3. Push the fuel pressure regulator onto the regulator housing on the fuel rail
4. Install a new fuel pressure regulator retainer (I)
5. Install or connect the following:
   • Fuel pressure regulator vacuum line
   • Negative battery cable
6. Tighten the fuel filler cap
7. Inspect for leaks using the following procedure:
   • Turn on the ignition with the engine off for two seconds
   • Turn off the ignition for 10 seconds
   • Turn on the ignition with the engine off
   • Inspect for fuel leaks
8. Install the fuel injector sight shield
9. Road test the vehicle to check performance

A fuel pressure regulator is located on the injector rail. It generally looks like a round chrome or black diaphragm with a vacuum line attached.
This is what controls the amount of fuel the injector get. They are fairly simple to replace, just shut off the car, make sure that you have released all the pressure in the fuel rail and then remove the regulator by removing the 2 (Generally 2) mounting screws and the vacuum line. Re install in reverse order and that's it.

Release fuel pressure by removing fuel pump relay and turning engine over to release pressure. Place a rag to catch any fuel under regulator Fuel pressure regulator has a locking clip pry clip off remove vacuum line pull regulator out with twisting motion,replace fuel pressure regulator install clip connect vacuum line install relay. Check for leaks,your done.

The 93-94-95 all have this problem ..the fuel line that come into the back do split and leak ..other problem is with vaccum lines coming off the back of intake and vacuum lines come apart from a 3 way fitting.located fire wall .when these are off will cause gas smell and bad millage .... hopes this helps...

Bad fuel pressure regulator. Located on drivers side of engine on fuel rail. Cost of part is around $70. Easy to replace. Buy the part, look at it, find the old one on the engine in the area described above. Pull the vacuum line off of it, if you see any fuel in the vacuum line it's bad. The vacuum line sucks up the fuel flooding the engine. Classic symptoms. Make sure to relieve the fuel pressure prior to removing or let it sit for a couple of hours, or over night. The leak will relieve the pressure over time. Simple clip holds it on, easy to get at. Make sure to remove both "O" rings prior to putting new unit on. Should solve the problem.