DESCRIPTION
The hot idle compensator (HIC) unit is located on the air cleaner and supplies additional air to intake manifold during high temperatures at idle. This helps maintain the proper air/fuel mixture under these conditions.
OPERATION
A thermo wax portion of the hot idle compensator (HIC) valve is located inside air cleaner. This thermo wax responds to temperature conditions. When it senses a high-heat condition, it opens to allow some air to flow directly from the air cleaner to the intake manifold.
Hot Idle Compensator Valve. Scheme 17
Carbureted Corolla and Tercel
- Remove HIC valve from air cleaner. Block atmospheric port and blow through heated air cleaner port. Air should pass through carburetor port.
- Blow through carburetor port. No air should escape from heated air cleaner port. With valve below 72°F (22°C), block carburetor port and blow through heated air cleaner port. No air should escape from atmospheric port.
- Heat valve in hot water. DO NOT allow water inside valve. Block carburetor port and blow through heated air cleaner port. Air should pass through atmospheric port when valve is above 84°F (29°C). (Scheme 17)
Land Cruiser
- Remove HIC valve from air cleaner. With valve below 81°F (27°C), block intake manifold port and blow through heated air cleaner port. No air should escape from atmospheric port.
- Heat valve in hot water. DO NOT allow water inside valve. Block heated air cleaner port and blow through intake manifold port. When valve is between 81-122°F (27-50°C), a small amount of air should pass through atmospheric port. A large amount of air should pass through atmospheric port when valve is above 185°F (85°C).
| Application | Minimum Temp. °F (°C) | Maximum Temp. °F (°C) |
|---|---|---|
| Land Cruiser | 81-122 (27-50) | Above 185 (85) |
| All Others | 84-126 (29-52) | Above 192 (89) |
HOT IDLE COMPENSATION OPERATING TEMPERATURES