How to Replace 6.5L Injectors

by James Marshall

The 6.5-liter engine introduced by General Motors in 1992 was a diesel engine that was frequently turbocharged. It was an option for many full-size Chevrolet and GMC pickup trucks from 1992 to 1999. The fuel injectors in the 6.5-liter deliver diesel fuel to the engine at precise intervals to maximize fuel efficiency. The replacement of the fuel injectors in this engine requires you to remove additional components to access the injectors.

Remove the cable from the negative terminal of the battery with a socket wrench to ensure you don't accidentally start the engine. Release the clip that connects the fuel return line to the fuel injectors and detach the fuel line.

Remove the mounting bolt that attaches the the air cleaner bracket to the valve cover with a socket wrench, and detach the air cleaner bracket from the valve cover. Disconnect the bracket for the crankcase ventilator. Detach the fuel lines to the secondary fuel filter and disconnect the secondary fuel filter.

Release the clamp that holds the vacuum pump in place and move the pump to gain access to the mounting bolts for the intake manifold. Disconnect the mounting bolts with a socket wrench and remove the intake manifold. Place a cover such as GM part no. J-29664-1 to keep debris out of the engine.

Release the clips that attach the fuel injection lines to the loom brackets. Detach the fuel injection lines from the fuel injector nozzles and place caps on the fuel injector nozzles. Disconnect the fuel lines from the fuel injection pump.

Grip the 30mm hex portion of each fuel injector with GM special tool J-29873 and turn the injector counterclockwise to remove it. Remove and discard the fuel injector gaskets. Place a protective cap on the open end of each fuel injector to keep debris out of the fuel injector.

Mount a new gasket to each new fuel injector. Attach GM special tool J-29873 to a torque wrench and install the fuel injector by turning it clockwise with the special tool. Torque the fuel injector to 50 ft. lbs.

Perform steps one through four in reverse sequence to complete the installation of the fuel injectors. Tighten the fittings for the fuel injection lines to 20 ft. lbs. with a torque wrench. Tighten the mounting bolts for the secondary fuel filter to 30 ft. lbs. Tighten the bolts that connect the fuel line to the secondary fuel filter to 9 in. lbs.

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About the Author

James Marshall began writing professionally in 2006. He specializes in health articles for content providers such as eHow. Marshall has a Bachelor of Science in biology and mathematics, with minors in chemistry and computer science, from Stephen F. Austin University.

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