Mopar MD158484 Fuel Injector

If the rpm change is consistent across cylinders, the injectors are functioning correctly; if not, proceed to the next injector. If the injectors are operating properly, check the ignition system, spark plugs, and wires, and perform a compression check if needed.

First remove the air cleaner assembly and relieve the fuel system pressure. Disconnect the negative battery cable and remove the fuel pressure regulator if necessary. Remove the Torx screw and carefully pry off the injector cap. Use a small screwdriver to gently pry the injector from the throttle body. Peel off the upper and lower O-rings from the injector, making sure to retrieve the lower O-ring if it is not on the injector.

With the engine running or cranking, listen to the sound from each injector with an automotive stethoscope and verify the injectors are all clicking the same. If you don't have a stethoscope, place the tip of as crew driver against the injectors and press your ear against the handle of the screwdriver. Also feel the operation of each injector with your finger. It should sound/feel smooth and uniform and its sound/feel should rise and fall with engine RPM. If an injector isn't operating, or sounds/feels erratic check the injector connector and the wire electrical connector. If the connectors are snug, check for voltage to the injector, using a special injector harness test light (available at our website).