How to Replace a Fuel Injector in Chevrolet Cars

by Contributing Writer; Updated June 12, 2017

A Chevrolet car uses with one of two basic factory fuel injection systems. The early Chevrolet car came equipped with a throttle body injection system that featured injectors mounted in a throttle body design that was similar in appearance to a carburetor. The later models were equipped with port fuel injection that featured a single injector per cylinder, mounted in the intake manifold runner. Replacing the injectors in either of these systems is well within the average mechanic's capability and requires only basic hand tools. If you have difficulty determining your fuel injection system, check your owner's manual.

Under The Hood:

 How to Replace a Fuel Injector in a Geo Tracker

Determine which fuel injector your Geo Tracker will need. This depends not only on the make and model, but also the engine size. Models made from 1989 to 1998 have a 1.6L engine and a 2.0L engine was added for models made after 1998.

Relieve the fuel system pressure and disconnect the negative battery cable with a socket wrench. Separate the air intake case from the throttle body.

Remove the clamp for the fuel send line from the intake manifold with a socket wrench and disconnect the fuel line from the throttle body. Insert clean cloths into the throttle body to prevent debris from dropping into the engine. Loosen the screws on the fuel injector cover with a Phillips screwdriver and remove the cover.

Disconnect the coupler for the fuel injector, release its electrical harness from the clamp and remove the grommet from the throttle body. Place a cloth over the injector and one hand on top of the cloth. Use an air gun to gently blow air into the fuel inlet port of the throttle body to unseat the fuel injector. Remove the injector from the throttle body.

Install the new fuel injector by reversing the removal procedure. Lubricate the new O-rings with a thin coat of gasoline before you install them. Apply a thin coat of locking compound to the screws on the fuel injector cover.

Replace the remaining components and turn the ignition switch on without starting the engine. Pressurize the fuel system and check for fuel leaks.

Items you will need

  • Air gun

  • Clean cloths

  • Fuel injector kit

  • Phillips screwdriver

  • Socket wrench set

  • Locking compound

  • Torque wrench

 How to Change Fuel Injectors in a Chevy S-10

Throttle Body Injection

Remove the air cleaner to gain access to the throttle body. Set the air cleaner, air filter and wing nut in a safe place to avoid damage. Unplug the injector harness attached to the injectors.

Remove the top of injector housing and fuel pressure regulator assembly by removing the T-10 torx head screws. Then gently pry the assembly up to expose the injectors located in the throttle body below.

Remove the old injectors by gently prying up on the injector, and take note of the order that the seals are installed. The upper seal consists of a thin metal ring and rubber o-ring seal. Then install the new injectors, the metal ring and the rubber o-ring in that order.

Re-assemble the upper injector housing. Replace the paper gasket and tighten the T-10 Torx screws securely. Plug the injector harness back on to the injectors and start the engine. Check for leaks.

Re-install the air cleaner and air filter, and tighten the wing nut securely.

Port Fuel Injection

Remove any engine covers and air cleaner ducts to gain clear access to the fuel injector rail that the injectors are mounted in. Unplug the injector wiring from the injectors.

Remove the fuel filler cap to relieve pressure and disconnect the fuel lines from the injector rail using open-end wrenches.

Remove the 10mm bolts that secure the injector rail to the manifold. Remove the fuel rail and injectors as a unit.

Remove the lock clips that hold the injectors to the fuel rail, and twist the injectors as you pull to remove them from the rail. Lubricate the injector seals with silicon grease. Install the injectors in the fuel rail, and snap the retaining clips into place to hold them securely.

Position the injectors into the openings in the manifold and press the rail down until the injectors are seated in the manifold. Install and tighten the 10mm retaining bolts securely and reconnect the fuel lines.

Reconnect the injector wiring harness to the injectors and reinstall the air filter housing. Prime the fuel system by turning the ignition key to the "on" position, then to "off." Do this two more times. Check for leaks, then start the engine.

Items you will need

  • 1/4 inch-drive socket set

  • Metric wrench set

  • Screwdriver set

  • Torx driver set

  • Injectors

  • Gasket set

 How to Change Fuel Injectors on a 2002 Chevy Trailblazer

Six-cylinder models

Relieve the fuel system pressure by first removing the fuel filler cap and then the fuel pump relay, located in the fuse box under the hood. Start the engine and allow it to stall, then continue to crank the engine an additional five to 10 seconds.

Disconnect the negative battery cable from the terminal.

Remove the intake manifold by first removing the throttle body and PCM. Disconnect the electrical harnesses from their brackets and the MAP sensor connector. Disconnect the front differential vent hose from its bracket clip. Disconnect the crankcase vent hose from its port on the manifold. Remove the engine harness bracket and alternator. Disconnect the vacuum hose from the power brake booster and then remove the intake manifold by unscrewing the bolts.

Clean the fuel rail/fuel injector area with degreaser. Blow the area dry with compressed air.

Disconnect the fuel pressure regulator vacuum line, the fuel injector harness connector and the fuel line fittings. Remove the fuel rail attaching bolts and apply gentle and even outward pressure on the fuel rail to free it from the cylinder head.

Disconnect the electrical connector from the injectors to be removed. Remove the retaining clips and remove the injectors from the fuel rail assembly. Remove and discard the O-rings and seals (two per injector).

Replace the injector O-rings. Apply a light coat of clean engine oil to the O-rings and press the injector into the fuel rail until seated. Install the injector retaining clips.

Inspect the injector holes on the cylinder head and clean out if necessary. Lubricate the injector seal O-rings with clean engine oil and seat them on the injector holes. Reconnect the electrical connector to the injector.

Replace the fuel rail assembly and tighten the mounting bolts to 89 in-lbs.

Continue with the installation in the reverse of removal. Once complete, turn the ignition switch to "On" but do not engage the starter. Cycle the ignition on and off several times to activate the fuel pump and build fuel pressure. Check the fuel lines, fuel rail and injector for leakage prior to full operation.

V8 models

Relieve the fuel system pressure by first removing the fuel filler cap and then the fuel pump relay, located in the fuse box under the hood. Start the engine and allow it to stall, then continue to crank the engine an additional five to 10 seconds.

Disconnect the negative battery cable from the terminal.

Remove the air intake duct and resonator by removing the diagonal brace and intake baffle. Loosen the captive screws and pull the housing cover up, then lift the air filter element out of the housing. Disconnect the headlamp washer hose and the electrical connectors for the windshield washer, headlamp washer, fluid level and water pump. Disconnect the forward lamp harness clips and washer fluid hose. Remove the housing mounting nuts and remove the housing.

Disconnect any electrical connectors that will interfere with fuel rail removal. Detach the upper engine wiring harness from the retainers and position the wiring harness aside. Disconnect the accelerator cable and cruise control cable from the throttle body. Detach the cables from the bracket and position the cables aside.

Clean the fuel rail/fuel injector area with degreaser. Blow the area dry with compressed air.

Disconnect the fuel injector electrical connectors by pulling the retainer up and pushing in on the tab. Tag each connector with a number that corresponds to the cylinder number. Disconnect the fuel supply and return lines from the fuel rail pipes. Disconnect the fuel vacuum line from the fuel pressure regulator.

Remove the fuel rail mounting bolts. Loosen the crossover tube retaining screw at the passenger side of the fuel rail but do not remove the tube. Gently rock the fuel rail and injectors to loosen the injectors. Remove the fuel rail and fuel injectors as an assembly.

Remove the retaining clip and remove the injectors from the fuel rail assembly with a forked tool. Remove and discard the O-rings and seals.

Replace the injector O-rings and apply a light coat of clean engine oil. Press the injector into the fuel rail until seated. Install the injector retaining clips.

Install the injector and fuel rail assembly on the intake manifold and fully seat the injectors. Apply a thread-locking compound to the fuel mounting bolts and tighten them to 89 in-lbs. Tighten the crossover tube retainer screw at the right fuel rail.

Connect the fuel supply and return lines; verify they are securely installed. Connect the electrical connectors to each injector according to the number as tagged.

Continue with the installation in the reverse of removal. Once complete, turn the ignition switch to "On" but do not engage the starter. Cycle the ignition on and off several time to activate the fuel pump and build fuel pressure. Check the fuel lines, fuel rail and injector for leakage prior to full operation.

Items you will need

  • Screwdriver

  • Degreaser

  • Compressed air

  • Socket wrench

  • Sockets

  • Straight wrench

  • Torque wrench

  • Fuel injector

  • Fuel injector O-rings

  • Forked tool

  • Engine oil

  • Thread-locking compound

 How to Replace Fuel Injectors on a Cavalier

Remove the Injector

Remove the fuel pump fuse or relay to relieve fuel system pressure.

Start the engine and let it idle until it stalls. Then crank the engine for about three seconds to relieve any remaining pressure.

Detach the ground battery cable using a wrench.

Disconnect the fuel line from the fuel rail located around the top of the engine. On fuel lines with a metal collar, use a quick disconnect tool of the appropriate size for your particular model. If your Cavalier model uses a plastic collar on the fuel line, squeeze the plastic tabs on the connector and pull the line off the fuel rail.

Wipe both the connector and fuel rail ends using a clean shop rag.

Unscrew the mounting bolts from the fuel rail to detach it from the engine using a ratchet, ratchet extension and socket. Then, carefully lift the rail and fuel injector assembly from the engine.

Unplug the electrical connector from the injector or injectors you need to replace.

Pull the retaining clip from the injector or injectors you need to replace using a pair of needle nose pliers, if necessary.

Pull the injector(s) carefully from the fuel rail, making sure to remove the O-ring from the top of the injector.

Install the New Injector

Install a new O-ring onto the top and bottom of the injector or injectors you are replacing. Then, carefully attach the injector to the fuel rail.

Insert the retaining clips on the injector(s).

Plug the electrical connector to the injector(s).

Set the fuel rail in place around the top of the engine, making sure the tip of each injector enters properly in their respective intake ports. Then screw the mounting bolts using a ratchet, ratchet extension and socket.

Apply a light coat of new engine oil to the connecting ends of the fuel rail assembly and the fuel line.

Push the fuel line quick-connect fitting into the fuel rail end until the fitting lock or tabs snap in place. Then, slightly pull on the fuel line to make sure it is properly connected.

Install the fuel pump fuse or relay.

Attach the ground battery cable using the wrench.

Items you will need

  • Wrench

  • Quick disconnect tool

  • Clean shop rag

  • Ratchet, ratchet extension and socket

  • Needle nose pliers

  • New O-rings

  • New engine oil

 How to Replace a Fuel Injector in a Chevy Silverado

Determine which fuel injector your Chevy Silverado will need. You'll want to be sure the new fuel injector is compatible with your Silverado's engine. Models are equipped with a Vortec 4.3L, 4.8L, 5.3L or 6.0L engine depending on the exact model.

Disconnect the negative battery cable and remove the bolts from the engine sight shield bracket with a socket wrench. Detach the cables for the accelerator control and cruise control from the cable bracket and throttle body. Use a socket wrench to remove the retainer nut for the upper engine wire harness so you can move the upper engine wire harness aside.

Label the fuel injector connectors for future reference and pull the top part of the injector connector up without pulling it past the top of the white portion. Push the tab on the lower side of the connector to release it from the injector.

Detach the fuel send and return lines from the fuel rail with a socket wrench. Remove the fuel pressure regulator vacuum line and the crossover tube-to-right fuel rail retainer screw. Unfasten the mounting bolts for the fuel rail so you can remove the fuel rail.

Insert the fork of a fuel injector assembly removal tool between the fuel rail pod and the three retaining clip ledges. Pry the fuel injector out of the fuel rail pod and discard the O-ring seals and retainer clip.

Install the new fuel injectors by reversing the removal procedure. Lubricate the injector O-ring seals with clean engine oil prior to installation.

Apply a 5mm band of threadlock to the fuel rail retaining bolts and use a torque wrench to tighten them to 89 inch pounds. Torque the crossover pipe retaining screw to 34 inch pounds, the upper engine wire harness retainer nut to 49 inch pounds and the engine sight shield bolts to 89 inch pounds.

Items you will need

  • Fuel injector assembly removal tool

  • Fuel injector kit

  • Socket wrench set

  • Torque wrench

  • Threadlock

 How to Replace a Fuel Injector in a Chevy Camaro

Determine which fuel injector your Chevy Camaro will need. This depends not only on the make and model, but also the engine size. Models made from 1967 to 1969 were available in a variety of engine sizes including 3.8L, 4.0L, 4.9L, 5.4L, 5.7L, 6.5L, 6.6L and 7.0L.

Look at engine sizes for additional Camaro models. The second generation Camaro covers the years 1970 to 1981 and was offered with 3.8L, 4.1L, 5.7L, 6.5L, 6.6L and 7.4L engines. The third generation was made from 1982 to 1992 and came with 2.5L, 2.8L, 3.1L, 5.0L and 5.7L engines. Models made from 1993 to 2002 had the option of a 3.3L, 3.8L or 5.7L engine.

Disconnect the negative battery cable with a socket wrench and relieve the fuel system pressure. Remove the fuel send and return lines from the fuel rail and detach the fuel injector electrical connectors.

Detach the vacuum hose from the fuel pressure regulator, unplug the manifold absolute pressure sensor electrical connector and disconnect the vacuum line from the fuel pipe bundle.

Remove the fuel injector harness fasteners and the mounting bolts for the fuel rail with a socket wrench. Release the retainer clips for the fuel injectors and remove the fuel injectors. Discard the old O-rings.

Install the new fuel injectors by reversing the removal procedure. Coat the injector O-rings with clean engine oil prior to installation. Use a torque wrench to tighten the mounting bolts for the fuel rail to 89 inch pounds.

Items you will need

  • Fuel injector kit

  • Socket wrench set

  • Torque wrench

 How to Replace a Fuel Injector in a Chevy Cobalt

Determine which fuel injector your Chevy Cobalt needs. This depends not only on the make and model, but also the engine size. You will have one of the following engines: 2.0 L S/C LSJI4, 2.0 L Turbo LNFI4, 2.2 L L61I4, 2.2 L LAPI4 or 2.4 L LE5I4.

Disconnect the negative battery cable with a socket wrench and relieve the fuel system pressure. Remove the coolant overflow pipe and disconnect the fuel supply pipe from the fuel rail with a back-up wrench. Unfasten the mounting studs on the fuel rail with a socket wrench.

Pull the fuel rail back and upward to remove the fuel injectors from the cylinder head ports. Rotate the fuel rail so that the injectors are positioned downward and then remove the fuel rail.

Remove the wiring harnesses for the fuel injectors. Release the retainer clip for the fuel injectors and remove the fuel injectors. Remove and discard the fuel injector O-rings.

Install the new fuel injectors by reversing the removal procedure. Lubricate the new injector O-rings with clean engine oil.

Use a torque wrench to tighten the fuel rail studs to 89 in. lbs. and torque the bolts on the fuel supply pipe to 10 ft. lbs. Torque the bolt for the coolant overflow pipe to 71 in. lbs.

Turn the ignition on for 2 seconds, off for 10 seconds and start the engine to check for fuel leaks.

Items you will need

  • Back-up wrench

  • Fuel injector kit

  • Socket wrench set

  • Torque wrench

 How to Replace a Fuel Injector in a Chevy Impala

Determine which fuel injector your Chevy Impala will need. This depends not only on the make and model, but also the engine size. The first generation of the Impala covers 1958 to 1961 and these models were available with 235 cubic inch (ci), 283ci, 348ci and 409ci engines. Second generation models made from 1962 to 1964 may have a 230ci, 283ci, 327ci or 409ci engine.

Look at later generations of the Impala. The third generation was made from 1965 to 1970 and was offered with 250ci, 283ci, 307ci, 350ci, 396ci, 409ci and 427ci engines. The fourth generation Impala covers 1971 to 1976 and was available with 350ci, 400ci and 454ci engines.

Check the engine sizes for more recent versions of the Impala. The fifth generation was made from 1977 to 1985 and may be equipped with 229ci, 231ci, 250ci, 267ci, 305ci, 350ci or a 350 diesel engine. The sixth generation of the Impala covers 1994 to 1996 and has a 5.7L engine.

Examine the engine size for the latest models of the Chevy Impala. The seventh generation was made from 2000 to 2005 and is available with 3.4L and 3.8L (supercharged and non-supercharged) engines. The latest generation debuted in 2006 and may have a 3.5L, 3.9L or 5.3L engine.

Disconnect the negative battery cable with a socket wrench and relieve the fuel system pressure. Remove the fuel injector sight shield with a socket wrench and disconnect the fuel send and return lines.

Remove the fuel pressure regulator vacuum hose and ignition coil wires from the coil. Disconnect the electrical connectors from the fuel injectors. Remove the fuel rail mounting nuts with a socket wrench, release the retaining clips for the fuel injector and remove the fuel injectors. Discard the old O-rings.

Install the new fuel injectors by reversing the removal procedure. Coat the new fuel injector O-rings with clean engine oil. Use a torque wrench to tighten the fuel rail mounting bolts to 7 foot pounds and torque the mounting nuts for the fuel injector sight shield to 27 inch pounds.

Items you will need

  • Fuel injector kit

  • Socket wrench set

  • Torque wrench

About the Author

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