Three Way Servo Diaphragm

Fig. 54 Applying Direct Intake Manifold Vacuum To Servo Diaphragm.:

Fig. 49 Idle Up Adjustment Screw.:

1. Warm up the engine and run it at idle.
2. Attach a tachometer to the engine.
3. Disconnect the solenoid vacuum hose form servo diaphragm port (A).
4. Apply the intake manifold vacuum directly to servo diaphragm.
5. Increase the engine speed to 2,000 rpm with the throttle lever, then release it.
6. Confirm that the engine speed is within standard speed.

Caution
All accessories should be OFF.

Standard engine speed:
1,300 - 1,400 rpm..................MTX
1,400 - 1,500 rpm..................ATX

7. If the engine speed does not agree with the standard value, turn the adjust screw to obtain the standard speed.



8. Reconnect the solenoid valve vacuum hose to port (A) and the valve.
9. Disconnect the solenoid valve vacuum hose from the servo diaphragm port (B).
10. Attach the intake manifold vacuum directly to the servo diaphragm. Increase the engine speed to 2,000 rpm, using the throttle lever, then release it.
11. Confirm that the engine speed is within the standard value.

Standard engine speed:
1,100 - 1,300

Fig. 55 Three Way Servo Diaphragm.:

12. If the engine speed does not agree with the standard value, disconnect the vacuum hose and turn the adjust screw (B) on the diaphragm head to obtain the correct speed.

Note:
Engine speed is increased when the adjust screw is turned counter-clockwise and decreased when the adjust screw is turned clockwise.

13. Connect the engine vacuum hose to port (B) and reconfirm the engine speed.
14. Reconnect the solenoid valve vacuum hoses for port (B) and the valve.
15. Disconnect the vacuum tube from the servo diaphragm port (C).
16. Attach the intake manifold vacuum directly to port C of the servo diaphragm. Increase the engine speed to 2,000 rpm, using the throttle lever, then release it.
17. Confirm that the engine speed is within the standard value.

Standard engine speed:
950 - 1,050 rpm....................(MTX)
1,100 - 1,200 rpm....................(ATX)

18. If the engine speed does not agree with the standard value, disconnect the vacuum hose and turn the adjust screw (C) on the diaphragm head to obtain the correct speed.

Note:
Engine speed is increased when the adjust screw is turned counter-clockwise and is decreased when the adjust screw is turned clockwise.

19. Reconnect the engine vacuum hose to port (C) after adjusting and reconfirm the engine speed.
20. Reconnect the solenoid valve vacuum hoses for port (C) and the solenoid valve.