Warning: Gasoline is extremely flammable, so take extra precautions when you work on any part of the fuel system. See the Warning in Fuel pressure relief procedure.
Warning: The fuel delivery system on 2.7L, 3.3L, 3.5L turbocharged models and 2018 and later 5.0L models is made up of a low-pressure system and a high-pressure system. Once the pressure on the low-pressure side of the system has been relieved, wait at least two hours before loosening any fuel line fittings in the engine compartment.
Warning: Wait until the engine is completely cool before beginning this procedure.
Fuel rails
1. Relieve the fuel pressure (see Fuel pressure relief procedure).
2. Disconnect the cable from the negative terminal of the battery (see Battery – disconnection and reconnection).
Removal
2.7L models
3. Remove the intake manifold (see Intake manifold(s) – removal and installation).
4. Use compressed air to clean the area around the fuel injectors and fuel rails to prevent debris from entering the fuel system or engine.
5. Remove the high-pressure fuel pump cover on the rear of the passenger’s (right) cylinder head.
6. On 2018 and later models, remove the port fuel injection fuel rails and injectors.
7. If removing the passenger’s (right) fuel rail, remove and discard the fuel feed pipe between the high-pressure fuel pump and the fuel rail (see High-pressure fuel pump – removal and installation).
High-pressure fuel pipe (A) and fuel rail mounting bolts (B) (2.7L model shown)
8. Remove and discard the high-pressure fuel pipe between the rear of the two fuel rails
9. Disconnect the fuel injector harness electrical connectors at the rear of the engine.
10. Remove the fuel rail mounting bolts.
11. Carefully pull the fuel rail with the fuel injectors out of the intake manifold at the same angle as the fuel injectors. Use a slight wiggle motion to assist in breaking the fuel injectors free from the cylinder head.
Caution: Any injectors that remain stuck in the cylinder head must be removed using a special injector removal tool that uses a slide-hammer type procedure to remove any stuck injectors.
Note: If the isolator on the bottom of the fuel injector falls off during removal, replace the fuel injector
12. Disconnect the fuel injector connectors, remove and discard the injector clips and pull the injectors from the fuel rail. See the Fuel injector seals — replacement information in this section.
3.3L, 3.5L non-turbo and 5.0L models — port fuel injection fuel rails and injectors
13. On the 3.3L Duratec and 3.5L non-turbo models, remove the upper intake manifold (see Intake manifold(s) – removal and installation).
14. On 5.0L models, remove the engine cover.
15. On all models, disconnect the fuel rail supply hose quick-connect fitting.
16. Remove the left and right insulators covering the fuel rails.
17. Cover the disconnected fuel feed hose and fuel rail fitting and use compressed air to clean the area around the fuel injectors and fuel rails to prevent debris from entering the fuel system or engine.
18. Disconnect the fuel injector harness connectors.
19. Remove the fuel rail mounting bolts securing the fuel rails to the lower intake manifold.
20. Carefully pull the fuel rail with the fuel injectors out of the intake manifold. Use a slight wiggle motion to assist in breaking the fuel injectors free from the intake manifold.
21. Remove and discard the injector clips and pull the injectors from the fuel rail. See the Fuel injector seals — replacement information in this section.
3.5L turbocharged models —
2016 and earlier
22. Remove the engine cover and high-pressure fuel pump cover.
23. Remove the intake manifold (see Intake manifold(s) – removal and installation).
24. Use compressed air to clean the area around the fuel injectors and fuel rails to prevent debris from entering the fuel system or engine.
25. Drain the cooling system (see Service the cooling system (drain, flush and refill)).
26. Remove the three bolts and position the coolant crossover out of the way. Discard the 0-rings for the crossover and install new ones during installation.
27. Remove the coolant pipe running between the cylinder banks by firmly pulling the pipe towards the rear of the engine to disengage the front coupling. Discard the 0-rings for the coolant pipe ends and install new ones during installation.
28. Remove and discard the fuel feed line between the high-pressure fuel pump and the fuel rails. Remove the bolt attaching the fuel feed pipe to the intake manifold. The feed line is not be re-used; obtain a NEW feed line for installation.
29. Detach the harness from the fuel rails and disconnect the harness connectors and fuel rail pressure sensor connector from the rear of the engine.
30. Remove the fuel rail mounting bolts.
31. Carefully pull the fuel rail with the fuel injectors out of the intake manifold at the same angle as the fuel injectors. Use a slight wiggle motion to assist in breaking the fuel injectors free from the cylinder head.
Caution: Any injectors that remain stuck in the cylinder head must be removed using a special injector removal tool that uses a slide-hammer type procedure to remove any stuck injectors.
Note: If the isolator on the bottom of the fuel injector falls off during removal, replace the fuel injector.
32. Disconnect the fuel injector connectors, remove and discard the injector clips and pull the injectors from the fuel rail. See the Fuel injector seals — replacement information in this section.
3.3L, 3.5L turbo and 2018 and later 5.0L models — Direct Injection (DI) fuel rails
33. Remove the intake manifold (see Intake manifold(s) – removal and installation).
34. Remove the port injection fuel rail insulator.
35. Use compressed air to clean the area around the fuel injectors and fuel rails to prevent debris from entering the fuel system or engine.
36. Disconnect and remove the fuel line between the left and right port injection fuel rails (see Fuel lines and fittings – general information and disconnection).
37. Disconnect the port injection fuel rail electrical connectors at the rear of the fuel rails.
38. Remove the fuel rail mounting bolts securing the fuel rails to the engine.
39. Carefully pull the fuel rail with the fuel injectors out of the cylinder head. Use a slight wiggle motion to assist in breaking the fuel injectors free from the head.
Caution: Any injectors that remain stuck in the cylinder head must be removed using a special injector removal tool that uses a slide-hammer type procedure to remove any stuck injectors.
Note: If the isolator on the bottom of the fuel injector falls off during removal, replace the fuel injector.
40. Disconnect the fuel injector connectors, remove and discard the injector clips and pull the injectors from the fuel rail. See the Fuel injector seals — rep/acementinformation in this section.
41. Remove and discard the injector clips and pull the injectors from the fuel rail. See the Fuel injector seals — replacement information in this section.
Installation
42. Installation is reverse of removal, noting the following points:
- Coat the injector 0-rings with clean motor oil prior to installation into the fuel rail.
- Install the fuel injectors to the fuel rail using new injector clips.
- On port injection systems, coat the injector 0-rings with clean engine oil prior to installation into the manifold.
- On DI injectors, DO NOT lubricate the injector Teflon seals before installing the fuel rail and injectors to the engine.
- On all models, press firmly to seat the injectors when installing the fuel rail to the engine.
- On Dl systems, use NEW high-pressure fuel feed pipes.
- Secure the fuel rail assembly with the retaining bolts, install the fuel feed pipes and tighten to the torque listed in this Chapter’s Specifications.
- On 2016 and earlier 3.5L turbo models, refill the cooling system (see Tune-up and routine maintenance).
- Turn the ignition on and check for leaks.
Fuel injectors/seals —replacement
Note: Even if you only removed the fuel rail assembly to replace a single injector or a leaking 0-ring, it’s a good idea to remove all of the injectors from the fuel rail and replace all of the 0-rings at the same time.
Caution: Use care not to gouge or damage the injector surface when replacing the 0- rings and seals.
Direct Injection (DI) fuel injectors
Identifying DI injector components
A. Teflon ring
B. Inlet 0-ring
C. Support ring
D. Fuel inlet cap
43. Pull the Teflon ring away from the injector body as far as possible (to prevent damage to the injector body) and cut the old Teflon ring from the injector
Slide the Teflon seal onto the installation cone …
44. Special tools, available at most auto parts stores, are used to install the new Teflon ring. Install the Teflon seal onto the seal installation cone, then place the cone against the end of the injector and push the seal onto the injector and into its groove using the proper collar
… push the seal onto the injector and into its groove…
… then push and rotate the sizing tool over the seal
45. Slide the sizing collar onto the injector and, using a 180-degree rotating motion, push the tool over the seal (see illustrations). Rotate the tool 180-degrees in the opposite direction and remove it.
Injector upper 0-ring (1) and support ring (2)
46. Remove the inlet 0-ring and support ring. Note the installed position of the support ring as one side is different and has a bevel (the bevel faces the injector body).
47. Inspect the fuel inlet caps. Remove any debris clogging the cap. If the cap is deteriorated or comes off, it is OK to discard as it is not needed for proper operation of the fuel injector. If the cap is missing, check that it is not in the fuel rail and remove as necessary.
48. Remove the injector clips and pull the injectors from the fuel rail.
Remove the 0-rings from the top and bottom of each
49. Remove the injector 0-rings and install new ones
50. Lubricate the 0-rings with clean engine oil.
51. Ensure that the injector caps are clean and free of contamination.
52. Install the injectors to the fuel rail. Ensure the injector clips retain the injectors securely.
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