The Geo Tracker mixes fuel and air under pressure with a fuel injector. Carburetors previously performed this function passively but were rendered obsolete by fuel injectors in the late 1980s. A fuel injector's programmable firmware allows it to handle different fuels. A fuel injector is made up of only the nozzle and valve; it still requires the pump to pressurize the fuel.
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.
