2014 Jeep Wrangler JK Factory Service Manual 14 - Fuel System

INJECTOR(S), Fuel

OPERATION

The fuel injectors (1) are electrical solenoids. The injector contains a pintle that closes off an orifice at the nozzle end. When electric current is supplied to the injector, the armature and needle move a short distance against a spring, allowing fuel to flow out the orifice. Because the fuel is under high pressure, a fine spray is developed in the shape of a pencil stream. The spraying action atomizes the fuel, adding it to the air entering the combustion chamber.

The top (fuel entry) end of the injector (3) is attached into an opening on the fuel rail.

The nozzle (outlet) ends of the injectors (2) are positioned into openings in the intake manifold just above the intake valve ports of the cylinder head.

The injectors are energized individually in a sequential order by the Powertrain Control Module (PCM). The PCM will adjust injector pulse width by switching the ground path to each individual injector on and off. Injector pulse width is the period of time that the injector is energized. The PCM will adjust injector pulse width based on various inputs it receives.

Battery voltage is supplied to the injectors through the ASD relay.

The PCM determines injector pulse width based on various inputs.

REMOVAL

WARNING:

The fuel system is under constant pressure even with engine off. Before servicing the fuel rail, fuel system pressure must be released.

  1. Release fuel system pressure (Refer to 14 - Fuel System/Fuel Delivery - Standard Procedure) .

    2.  
  2. Disconnect and isolate the negative battery cable.

    CAUTION:

    When removing the fuel rail from the lower intake manifold, one or more fuel injectors may remain in the intake manifold resulting in residual fuel spilling onto the engine from the fuel rail.


    3.  
  3. Remove the air inlet hose, upper intake manifold, and fuel rail (2) (Refer to 14 - Fuel System/Fuel Delivery/RAIL, Fuel - Removal) .

    NOTE:

    Number 2 fuel injector removal shown, all other fuel injectors similar.


    4.  
  4. Remove the fuel injectors (1) from the fuel rail (2).

    NOTE:

    Number 2 fuel injector removal shown, all other fuel injectors similar.


    5.  
  5. Remove the fuel injectors (1) from the lower intake manifold.

    6.  
  6. Remove and discard all fuel injector O-ring seals (1).

    7.  

INSTALLATION

  1. Lightly lubricate new O-ring seals (1) with engine oil and install on the fuel injector (2).

    NOTE:

    Number 2 fuel injector installation shown, all other fuel injectors similar.


    2.  
  2. Install the fuel injectors (1) to the fuel rail (2).

    3.  
  3. Install the fuel rail, upper inlet manifold and air inlet hose (Refer to 14 - Fuel System/Fuel Delivery/RAIL, Fuel - Installation)

    4.  
  4. Connect the negative battery cable and tighten nut to 5 N·m (45 in. lbs.).

    5.  
  5. Start the engine and check for leaks.

    6.