Manual Transmission

Idle-up Control:

PURPOSE
Raises engine speed in responsed to added electrical and A/C load.

Diaphragm Functions:

APPLICATION
Models without A/C
Use diaphragm (A) for increasing idle speed for electrical load.
Models with A/C
Use diaphragm (B) for increasing idle speed for electrical load, diaphragm (A) for increasing idle speed due to A/C load.

LOCATION
^ Idle-up solenoid is on the firewall near the brake master cylinder.
^ Fast Idle Control Device (FICD), A/C idle-up solenoid, is on the firewall near the windshield wiper motor.
^ Idle-up actuator is on the carburetor.

Idle Up Control Linkages And Diaphragms:

OPERATION
FICD and idle up actuator have two stroke funtions with one diaphragm.
^ When (A) portion of adjusting screw is subjected to vacuum pressure, the rod moves toward the direction of the arrow.
And then, as the center sheet of the diaphragm touches the end of adjusting screw 1, the vacun line closes. Accordingly, the rod does not lift more than S1.
^ When nipple (B) is subbjected to vacuum pressure, the rod moves toward arrow direction by S2. And then, the stopper attatched directly to the diaphragm touches the inner wall of the actuator.
As S2 is larger than S1, the center sheet of the diaphragm remains in contact with adjusting screw 1.
The remainder between S2 and S1 is absorbed by the stroke change of spring 1 located between the diaphragm and the sheet.