schematics and diagrams: how to change fuel injector on 2005 gmc envoy?

Its a complete procedure,you have to follow to replace the fuel injectors.

The details with diagram is as follows :----

Fuel Rail (Supply Manifold) & Injectors:--

Removal & Installation

4.2L Engine

Before servicing the vehicle, refer to the Precautions section.

Relieve the fuel system pressure. Refer to the fuel system relief procedure in this section.

Remove or disconnect the following:

NOTE
Clean the fuel rail assembly with a suitable spray cleaner before proceeding. Never soak the fuel rail in a cleaning solvent.

Negative battery cable, if not done already

Intake manifold

Fuel pressure regulator vacuum line

Fuel feed and return pipes

Fuel injector in-line electrical connector

Fuel rail attaching bolts and fuel rail

Fuel injector harness connector from the fuel injectors

Injector retaining clip

Injector from the fuel rail

Retainer clip and O-ring seals from each end of the injector and discard

To install:

NOTE

Each injector is calibrated. When replacing the fuel injectors, be sure to replace it with the correct injector.

Lubricate the new injector O-ring seats with engine oil.

Install or connect the following:

O-rings on the injector

New retainer clip on the injector

Push the fuel injector into the fuel rail socket, making sure the connector faces outward. The retainer clip locks to a flange on the fuel rail injector socket.

Fuel rail assembly. Tighten the bolts to 89 inch lbs. (10 Nm).

Fuel feed and return lines to the rail

Fuel injector electrical connectors

Fuel pressure regulator vacuum line

Intake manifold

Negative battery cable

Turn the ignition ON for 2 seconds and then turn it OFF for 10 seconds. Again turn the ignition ON and check for leaks.

4.3L Engine

Before servicing the vehicle, refer to the Precautions section.

Relieve the fuel system pressure. Refer to the fuel system relief procedure in this section.

Remove or disconnect the following:

NOTE
Each injector is calibrated. When replacing the fuel injectors, be sure to replace it with the correct injector.

Negative battery cable

Fuel meter body electrical connection and the fuel feed and return hoses from the engine fuel pipes

Upper manifold assembly

Poppet nozzle out of the casting socket

Fuel meter body by releasing the locktabs

Lower hold-down plate and nuts

While pulling the poppet nozzle tube downward, push with a small prytool down between the injector terminals and remove the injectors.

To install:

Lubricate the new injector O-ring seats with engine oil.

Install or connect the following:

CAUTION
To reduce the risk of fire or injury ensure that the poppet nozzles are properly seated and locked in their casting sockets

O-rings on the injector

Fuel injector into the fuel meter body injector socket.

Lower hold-down plate and nuts. Torque the nuts to 27 inch lbs. (3 Nm).

Fuel meter body assembly into the intake manifold. Torque the fuel meter bracket retainer bolts to 88 inch. lbs. (10 Nm).

Fuel meter body into the bracket and lock all the tabs in place

Poppet nozzles into the casting sockets

Electrical connections

New O-ring seals on the fuel return and feed hoses.

Fuel feed and return hoses and tighten the fuel pipe nuts to 22 ft. lbs. (30 Nm)

Negative battery cable

Turn the ignition ON for 2 seconds and then turn it OFF for 10 seconds. Again turn the ignition ON and check for leaks.

Install the manifold plenum.

5.3L Engine

Before servicing the vehicle, refer to the Precautions section.

Relieve the fuel system pressure. Refer to the fuel system relief procedure in this section.

Remove or disconnect the following:

Negative battery cable, if not done already

A/C compressor pressure switch electrical connector

Wire harness from the clip on the cylinder head

Mass Airflow/Intake Air Temperature (MAF/IAT) sensor connector

Alternator electrical connector

Right side electrical connectors from the coil main electrical harness, Electronic Throttle Control (ETC) and fuel injectors.

To detach the injector connector: Matchmark the connectors, pull the Connector Position Assurance (CPA) retainer up 1 click. Push the tab on the connector in, then detach the injector connector.

WARNING
Be very careful when removing the fuel rail and injectors not to damage the connector terminals or injector spray tips

Electrical harness from the clips on the ignition coil bracket

Evaporative emission (EVAP) purge solenoid electrical connector

Knock Sensor (KS) electrical connector

Manifold Absolute Pressure (MAP) electrical connector

Main coil

Fuel injector electrical connector (right side)

Electrical harness from the clips on the ignition coil bracket

Upper engine wire harness retainer nut. Position the wire harness aside.

Fuel feed and return pipes from the rail

Fuel pressure regulator vacuum line

Fuel rail bolts

Fuel rail, after cleaning with a spray-type cleaner

Fuel injector from the fuel rail

Fuel injector retainer clip and discard

Fuel injector lower O-ring seals and discard

Fig. Exploded view of the fuel rail mounting-5.3L engine

Fig. Exploded view of the fuel injector (3), retainer (1) and O-ring seals (2, 4)-5.3L engine

To install:

Install or connect the following:

New O-ring seals on the injectors, after lubricating with clean engine oil

New retainer clip on the injector

Fuel injector by pushing it into the fuel rail socket

Fuel rail

Apply 0.20 (5mm) band of threadlock to the threads of the fuel rail bolts

Fuel rail bolts and tighten to 89 inch lbs. (10 Nm)

Fuel pressure regulator vacuum line

Fuel feel and return pipes

Route the upper electrical harness into position over the engine.

Engine harness bracket nut and tighten to 89 inch lbs. (10 Nm)

PCV valve and hose

EVAP purge solenoid, KS, MAP sensor, main coil & fuel injector electrical connectors

Harness to the clips on the ignition coil bracket

Main coil, ETC, fuel injector electrical connectors

Harness to the clips on the ignition coil bracket

Alternator electrical connector

MAF/IAT sensor connector

Wire harness to the clip on the cylinder head

A/C compressor switch electrical connector

Air cleaner outlet duct

Fuel fill cap

Negative battery cable