Can the seal for the fuel line where it pushes onto the fuel rail be purchased seperately from the entire fuel line?G.M. only sells entire new line.

The rail is most likely not the problem, the fuel injector "O" ring seals are likely the problem in the rail.

Unbolt the fuel rail and lift up, then replace the injector seals (lightly oil seals) and reinstall new rail on injectors and push rail and attached injectors back into the intake holes, very easy job.

The fuel injector is held in place using rubber o rings in the fuel rail and intake manifold. You need to remove anything in the way to access the fuel rail. There will be 2 bolts securing the rail to the engine and gently pull up on the rail. In most cases the injector will seperate and you can do the replacement. In some cases the injector may be very hard to come out as the rubber seals may have dirt etc keeping them from seperating easily. Apply a light coating of synthetic grease to the new seals and reinstall

old post but see it asked many times.
assemble the rail first, its 1 piece so must be ready first.
3.7L Engine (FSM) RTM?
(1) If fuel injectors are to be installed, refer to Fuel
Injector Removal/Installation.
(2) Clean out fuel injector machined bores in
intake manifold.
(3) Apply a small amount of engine oil to each fuel
injector o-ring. This will help in fuel rail installation.
(4) Position fuel rail/fuel injector assembly to
machined injector openings in cylinder head.
(5) Guide each injector into cylinder head. Be careful
not to tear injector o-rings.
(6) Push right side of fuel rail down until fuel
injectors have bottomed on cylinder head shoulder.
Push left fuel rail down until injectors have bottomed
on cylinder head shoulder.
(7) Install 4 fuel rail mounting bolts and tighten.
Refer to torque specifications.
(8) Install 6 ignition coils. Refer to Ignition Coil
Removal/Installation.
(9) Connect electrical connectors to throttle body.
(10) Connect electrical connectors at all fuel injectors.
To install connector, refer to (Fig. 37). Push connector
onto injector (1) and then push and lock red
colored slider (2). Verify connector is locked to injector
by lightly tugging on connector.
(11) Connect necessary vacuum lines to throttle
body.
(12) Connect fuel line latch clip and fuel line to
fuel rail. Refer to Quick-Connect Fittings.
(13) Install air box to throttle body.
(14) Install air duct to air box.
(15) Connect battery cable to battery.
(16) Start engine and check for leaks.

first relieve the fuel pressure at the schrader valve. Use small plastic tool supplied with new filter to disconnect filter hose fitting at the fuel rail. Squeeze the tabs on the fitting and disconnect the fuel line from the filter, then remove the nuts and detach the filter. push the new disconnect fitting onto the new filter and lubricate both filter fittings weth clean engine oil. Install filter into bracket and puch the quick connect fitting onto the filter and fuel line, making sure they snap securely into place.

Check this procedure about V8 3.9L Fuel Injectors - Removal & Installation

1. Before servicing the vehicle, please familiarize yourself with safety procedures.
2. Relieve fuel system pressure.
3. Remove or disconnect the following:
   Negative battery cable Engine appearance covers Fuel lines Fuel pressure regulator Fuel cross over elbow Fuel injector connectors Fuel injector clamping plates Fuel injectors

To install:

1. Install or connect the following:
   Fuel injectors. Use new O-ring seals. Fuel injector clamping plates Fuel injector connectors Fuel cross over elbow Fuel pressure regulator Fuel lines Engine appearance covers Negative battery cable
2. Start the engine and check for leaks.
   

1. Before servicing the vehicle, please familiarize yourself with safety procedures.
2. Disconnect the negative battery cable.
   CAUTION The engine appearance cover is equipped with a noise suppressor. If the noise suppressor becomes separated from the engine appearance cover it must be positioned on the intake manifold prior to installing the engine appearance cover.
3. Remove the engine appearance cover and the noise suppressor, if detached.
4. Remove the air cleaner outlet pipe.
5. Release the fuel system pressure.
6. Remove the four engine appearance cover mounting bracket nuts and the brackets.
7. Disconnect the fuel pressure sensor electrical connector from the sensor.
8. Disconnect the fuel pressure sensor vacuum connector from the sensor.
9. Disconnect the eight fuel injector electrical connectors from the injectors.
10. Disconnect the fuel temperature sensor electrical connector from the sensor.
11. Disconnect the fuel supply tube retaining clip from the fuel injection supply manifold.
12. Disconnect the fuel supply tube spring lock coupling.
13. Remove the four bolts and the fuel injection supply manifold and fuel injectors as an assembly.
14. Remove the fuel injectors from the fuel injection supply manifold.
    CAUTION Use O-ring seals that are made of special fuel-resistant material. Use of ordinary O-ring seals can cause the fuel system to leak. Do not reuse the O-ring seals.
15. Remove and discard the 16 O-ring seals from the fuel injectors.
    
    
    

    Fig. Exploded view of the fuel injector mounting-3.9L engine shown
    

To install:

1. Lubricate the new fuel injector O-ring seals with clean engine oil before installing.
   CAUTION Use O-ring seals that are made of special fuel-resistant material. Use of ordinary O-rings can cause the fuel system to leak. Do not reuse the O-ring seals.
2. Install sixteen new O-ring seals onto the fuel injectors. Lubricate the O-ring seals with clean engine oil prior to installation.
3. Install the fuel injectors and clips onto the fuel rail.
4. Install the fuel rail and injectors as an assembly. Tighten the fuel rail bolts to 89 inch lbs. (10 Nm).
5. Install the remaining components in the reverse order of removal.

Keep us updated.

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

need to buy disconnect tool that slides around line and u push into connection and it releases the line all auto stores sell them their a few dollars

There is what is called a fuel rail. The fuel injector fits in between the fuel rail and the intake of the engine. If you look around the rail you will find a few bolts (usually 10mm) holding the rail in place. remove the rail bolts and gently pry up the rail. The injectors fit into each one with an o-ring sealing each side. Watch because sometimes the o-ring will stay in the rail or intake and you want to remove them before trying to put the new injector into it. If you have a little petroleum jelly, put a small amount on the o-ring before inserting it in the rail and intake. Line up all the injectors with the rail and intake and gently push them in. When all are lined up you can lightly tap the rail with a hammer, LIGHTLY tap it into place and reinstall the retaining bolts.

Hope this helps.

unbolt the filter from the bracket, that is a 5/16" machine screw head size, then remove the nylon clips that hold the lines onto the filter, hold a rag over the fuel line when u remove it, it will have about 30 pounds of pressure.