Fuel Injectors - All

This procedure covers the removal and replacement of all four fuel injectors on the 2015 Kia Forte 1.8L I4 engine, including fuel rail removal and fuel system depressurization.

Warnings

Tools required

Parts

• Fuel injector × 4 — OEM: 35310-2E100 or equivalent
• Fuel injector O-ring kit × 1 — Use OEM specification
• Fuel rail seal kit × 1 — Use OEM specification
• Engine cover gasket (if damaged) × 1 — Use OEM specification

Preparation

1. Ensure engine is completely cool to the touch
2. Park vehicle on level ground and engage parking brake
3. Disconnect negative battery terminal and wait 5 minutes for system depressurization
4. Place shop towels and drain pan under work area to catch fuel spillage
5. Remove engine cover by lifting firmly upward on front and rear sections

Procedure

1. 1

   Depressurize fuel system
   Locate the fuel pump fuse in the engine compartment fuse box (typically fuse #18, 15A labeled 'FUEL PUMP'). Remove the fuse, then reconnect the battery temporarily. Attempt to start the engine and let it run until it stalls from fuel starvation. Crank the engine 2-3 more times to ensure pressure is relieved. Disconnect the battery negative terminal again.
2. 2

   Disconnect intake air components
   Loosen the hose clamp at the throttle body connecting the intake air duct. Disconnect the breather hose from the air intake duct. Remove the air intake duct assembly to provide access to the fuel rail. Disconnect the electrical connector from the mass airflow sensor before removal.
   Torque spec

   Hose Clamps3 Nm (2 lb-ft)
3. 3

   Disconnect fuel supply line
   Locate the fuel supply line connection at the fuel rail on the driver's side. Place shop towels around the connection to catch residual fuel. Using the appropriate fuel line disconnect tool, depress the locking tabs and carefully disconnect the fuel line from the fuel rail. Expect approximately 30-50ml of fuel to drain. Cap the line to prevent contamination.
   ⚠Residual fuel under pressure may spray out. Wear safety glasses and have towels ready.
4. 4

   Disconnect electrical connections
   Disconnect the fuel injector wiring harness connector by pressing the release tab and pulling straight up. Disconnect all four individual fuel injector electrical connectors by pressing down on the locking tab and pulling the connector away from each injector. Label or photograph connections for reassembly reference.
5. 5

   Remove fuel rail mounting bolts
   Locate the two fuel rail mounting bolts securing the fuel rail to the intake manifold. Using a 10mm socket, remove both bolts completely. Keep bolts in a clean container for reinstallation.
   Torque spec

   Fuel Rail Bolts12 Nm (9 lb-ft)
6. 6

   Remove fuel rail assembly
   Carefully pull the fuel rail straight upward with even force to unseat all four fuel injectors from their bores simultaneously. Rock the rail gently side-to-side if resistance is felt, but do not pry or bend. Once free, lift the entire fuel rail with injectors still attached away from the engine. Place on a clean work surface.
7. 7

   Remove fuel injectors from rail
   Remove the injector retaining clip from each injector by sliding it off or prying gently with a flathead screwdriver. Pull each injector straight out of the fuel rail socket. Note the orientation of each injector. Remove and discard all old O-rings from each injector (two O-rings per injector - upper and lower).
8. 8

   Clean injector bores and fuel rail
   Inspect the fuel injector bores in the intake manifold for debris, carbon buildup, or damage. Clean gently with a lint-free cloth. Do not allow debris to fall into the manifold. Inspect fuel rail seats for damage or debris and clean thoroughly. Check fuel rail for cracks or damage.
9. 9

   Prepare new fuel injectors
   Lubricate new O-rings lightly with clean engine oil or gasoline. Install new upper and lower O-rings onto each new fuel injector, ensuring they are properly seated in their grooves without twisting. Verify each injector has the correct connector orientation and flow rating for this application.
   ℹ️Never reuse old O-rings. Always install new O-rings to prevent vacuum leaks and fuel leaks.
10. 10

    Install injectors into fuel rail
    Insert each fuel injector into the fuel rail socket with gentle twisting motion until fully seated. Install the retaining clip onto each injector, ensuring it locks into place securely. Verify each injector can rotate slightly but cannot be pulled out of the rail.
11. 11

    Install fuel rail assembly
    Position the fuel rail assembly over the injector bores, aligning all four injectors simultaneously. Apply even downward pressure on the fuel rail to seat all injectors into their bores. The injectors should press in smoothly without excessive force. Once fully seated, install both fuel rail mounting bolts finger-tight, then torque to specification in a cross pattern.
    Torque spec

    Fuel Rail Bolts12 Nm (9 lb-ft)
12. 12

    Reconnect fuel supply line
    Inspect the fuel line connection for damage. Install a new O-ring onto the fuel rail connection if provided in the seal kit. Push the fuel supply line onto the fuel rail connection until it clicks audibly into place. Tug gently to verify it is locked.
    ℹ️Connection must click audibly to confirm proper locking. A loose connection will cause fuel leaks and poor running.
    Torque spec

    Fuel Line Fittings25 Nm (18 lb-ft)
13. 13

    Reconnect electrical connections
    Reconnect each of the four fuel injector electrical connectors, pressing firmly until they click into place. Reconnect the main injector harness connector. Verify all connections are secure and properly seated.
14. 14

    Reinstall intake air components
    Reconnect the mass airflow sensor electrical connector. Install the air intake duct assembly, connecting it to the throttle body. Tighten the hose clamp at the throttle body to specification. Reconnect the breather hose to the intake duct.
    Torque spec

    Hose Clamps3 Nm (2 lb-ft)
15. 15

    Prime fuel system and check for leaks
    Reinstall the fuel pump fuse. Reconnect the negative battery terminal. Turn the ignition key to ON position (do not start) for 5 seconds, then OFF. Repeat this cycle 3-4 times to prime the fuel system. Inspect all fuel connections for leaks. Wipe any spilled fuel. Start the engine and allow it to idle while inspecting for fuel leaks around all injector seals and fuel line connections.
    ⚠️Monitor closely for fuel leaks during initial startup. Shut off engine immediately if leaks are detected.

Reassembly

1. Reinstall engine cover, ensuring all clips are properly seated
2. Verify all electrical connectors are secure and properly routed
3. Check that no tools or shop towels were left in engine compartment
4. Clean any spilled fuel from engine bay and surrounding surfaces

Verification

• Start engine and verify smooth idle with no misfires or rough running
• Check for fuel leaks around all injector seals and fuel line connections while engine is running
• Verify no fuel smell in engine compartment
• Use scan tool to check for any fuel system or misfire diagnostic trouble codes
• Test drive vehicle to confirm proper acceleration and engine performance under load
• Recheck for fuel leaks after test drive with engine at operating temperature

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