Idle Up Control Valve: Adjustments

Fig. 51 Applying Direct Intake Manifold Vacuum To Servo Diaphragm.:

1. Warm up the engine and run it at idle.
2. Attach a tachometer to the engine.
3. Disconnect the vacuum sensing hose from the servo diaphragm port (A).
4. Apply intake manifold vacuum directly to the servo diaphragm.

Fig. 49 Idle Up Adjustment Screw.:

5. Increase the engine speed to 2,000 rpm, using the throttle lever, then release it.
6. If the engine speed does not agree with the standard value, turn the adjust screw to obtain the correct speed.

Caution:
All accessories should be OFF.

Standard speed:
1,300 - 1,400 rpm........................A/C (MTX)
1,400 - 1,500 rpm........................A/C (ATX)
1,100 - 1,300 rpm..............................P/S

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

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

Fig. 52 Dual Servo Diaphragm Adjustment Screw.:

11. If the engine speed does not agree with the standard value, disconnect the vacuum hose and turn the adjust screw 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.

12. Reconnect the engine vacuum hose to port B and reconfirm the engine speed adjustment.
13. Reconnect engine and solenoid vacuum hoses.