Fuel pressure regulator — removal and installation (Opel Vectra A)

Note: Before you begin, see. Chapter 2.

Removal

Single overhead camshaft models (except Multec)

1. Disconnect the negative cable from the battery.

2. For improved access, remove the idle speed control valve as described in Chapter 22. Disconnect the wiring harness cover from the fuel injectors and move it to the side; be careful not to deform the wiring. Pull the casing, squeeze the wiring fastening clips to release the casing from the injectors.

3. Place a cloth under the pressure regulator to absorb any fuel that will leak out after 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 camshaft models (with Multec system)

6. Depressurize the fuel system as described in Chapter 8.

7. Remove the air block. If necessary, follow the instructions Chapter 5.

8. Disconnect the negative battery cable.

9. Note the pins of the cover location, carefully unscrew the screws of the fuel pressure regulator cover (size TX 15). Be careful not to let the spring fly out when removing the cover. Remove the cover spring support, 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 are worn or damaged, they can only be replaced as part of the upper half of the throttle body assembly.

Models with two overhead camshafts

11. Disconnect the negative cable from the battery.

12. Disconnect the electrical wiring from the air flow meter. Remove the O-ring.

13. Loosen the clamp screw securing the main air duct to the right end of the air flow 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 base of the air block, then remove the air block/air flow meter assembly.

15. Disconnect the two breather hoses at the rear 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 spill after removing the regulator.

19. Unscrew the four mounting bolts under the regulator, then remove the regulator.

Installation

20. Perform the installation in reverse order. Make sure that all wires, pipes, and hoses are properly connected. Please note that on models with two overhead camshafts (DOHC), the regulator's vacuum tube must run along 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 cover and diaphragm. Then place the cover on the mounting pins and tighten the fastening screws.
• c) Tighten the screws to the torque specified in the Specifications.

22. Finally, before starting the engine, check that there are no leaks in the regulator by creating pressure in the system by turning the ignition on and off.