How to Replace a Fuel Injector in a Jeep Grand Cherokeeby Contributor
The Jeep Grand Cherokee has a fuel injector that mixes fuel with air. This technology almost completely replaced carburetors in the late 1980s and its programmable firmware allows the same hardware to be used with different fuels. A fuel injector is only a nozzle and a valve; it still requires a pump to inject the fuel into the engine.
Determine which fuel injector your Jeep Grand Cherokee will need. This depends not only on the make and model, but also the engine size. Models made from 1999 to 2004 may be equipped with a 2.7L OM647, 3.1L 531, 4.0L PowerTech, or 4.7L PowerTech engine. Models made after this date can have a 3.0L OM642, 3.7L PowerTech, 4.7L PowerTech, 5.7L Hemi or 6.1L Hemi.
Relieve fuel system pressure and disconnect the negative battery cable with a socket wrench. Remove the air intake assembly and unplug the electrical connectors for the alternator.
Detach the fuel lines from the fuel injectors. Remove the vacuum hoses and electrical connectors from the throttle body with a socket wrench.
Unplug the electrical connectors for the fuel injectors, manifold absolute pressure sensor and intake air temperature sensor. Disconnect the ignition coils and mounting bolts for the fuel supply manifold with a socket wrench. This will allow you to remove the manifold with the injectors still attached. Discard the old O-rings.
Install the new fuel injectors by reversing the removal procedure. Use a torque wrench to tighten the mounting bolts for the fuel supply manifold to 20 foot pounds.
Start the engine and check for leaks.