Note: Before you start, see Chapter 2.
Removing
Single overhead cam models (except Multec)
1. Disconnect the negative cable from the battery.
2. For improved access, remove the idle speed control as described in Chapter 22. Disconnect the wiring harness cover from the fuel injectors, move it to the side; be careful not to deform the wiring. Pull the shroud, squeeze the wiring harness clips to release the shroud from the injectors.
3. Place a cloth under the pressure regulator to absorb the fuel that will leak out when the regulator is removed.
4. Loosen the clamp screws, disconnect the fuel supply hoses from the regulator.
5. Disconnect the vacuum pipe from the top of the pressure regulator, remove the regulator.
Single overhead cam models (with Multitec system)
6. Depressurize the fuel system as described in Chapter 8.
7. Remove the air block. If necessary, follow Chapter 5.
8. Disconnect the negative battery cable.
9. Notice the pins of the cover location, carefully unscrew the screws of the fuel pressure regulator cover (size TX 15). Make sure that the spring does not fly out when removing the cover. Remove the cover spring seat, spring and diaphragm, noting their location (see illustration).
10. The diaphragm must be replaced whenever the cover is removed. If any of the regulator components is worn or damaged, it can only be replaced as part of the upper half of the throttle body assembly.
Models with double overhead camshafts
11. Disconnect the negative cable from the battery.
12. Disconnect the electrical wiring from the airflow meter. Remove the O-ring.
13. Loosen the clamp screw securing the main air line to the right end of the airflow meter.
14. Using a socket wrench, remove the four bolts securing the air block to the throttle body. Lift the air block off the throttle body, disconnect the hose from the air block base, then remove the air block/airflow meter assembly.
15. Disconnect the two breather hoses on the back of the camshaft cover, and move them to the side.
16. Disconnect the wiring from the throttle position sensor.
17. Disconnect the vacuum pipe from the pressure regulator (see illustration).
18. Place a cloth under the regulator to absorb any fuel that will be spilled after the regulator is removed.
19. Under the regulator, unscrew the four mounting bolts, then remove the regulator.
Installation
20. Install in reverse order. Check that all wires, tubes and hoses are properly connected. Please note that on models with two overhead camshafts (DOHC), the regulator vacuum tube should run over the top of the breather hoses on the camshaft cover.
21. On models with the Multec system, also note the following:
- a) Install the new diaphragm so that it is located in the groove of the throttle body.
- b) Make sure that the spring and its support are correctly installed on the regulator cap and diaphragm. Then put the cover on the mounting pins, and tighten the fixing screws.
- c) Tighten the screws with the tightening force specified in the Specifications.
22. Finally, before starting the engine, check that there are no leaks in the regulator by pressurizing the system by turning the ignition on and off.
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