DESCRIPTION
The Hot Idle Compensator (HIC) helps maintain proper air/fuel mixture by supplying additional air to the intake manifold during high temperatures at idle. The HIC unit is located on the air cleaner.
OPERATION
A thermo wax portion of the HIC valve is located inside the 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.
Scheme 51
Scheme 52
Corolla (Carbureted), Corolla FX & Tercel Wagon
- Remove HIC valve from air cleaner. Block atmospheric port and blow through Hot Air Intake (HAI) port. Air should flow out of carburetor port. (Scheme 51)& (Scheme 52).
- Blow through carburetor port. No air should escape from HAI port. With valve temperature below 72°F (22°C), block carburetor port and blow through HAI port. No air should escape from atmospheric port.
- Heat HIC valve in hot water. DO NOT allow water inside valve. Block carburetor port and blow through HAI port. Air should pass through atmospheric port when valve temperature is above 84°F (29°C).
| Application | HIC Valve Temp. °F (°C) | |
|---|---|---|
| Corolla FX & Tercel Wagon | ||
| Minimum Opening | 84-126 (29-52) | |
| Partial Opening | 138-180 (59-82) | |
| Maximum Opening | Above 192 (89) | |
| Corolla (Carbureted) | ||
| Minimum Opening | 77-131 (25-55) | |
| Partial Opening | 131-203 (55-95) | |
| Maximum Opening | Above 203 (95) | |
HOT IDLE COMPENSATOR OPERATING TEMPERATURES
Tercel Sedan
- Remove HIC valve from air cleaner. Block atmospheric port and blow through HAI port. Air should flow out of carburetor port.
- Blow through carburetor port. No air should escape from HAI port. With valve temperature below 79°F (26°C), block carburetor port and blow through HAI port. No air should escape from atmospheric port.
- Heat HIC valve in hot water. DO NOT allow water inside valve. Block carburetor port and blow through HAI port. Air should pass through atmospheric port when valve temperature is above 93°F (34°C).
| Application | HIC Valve Temp. °F (°C) | |
|---|---|---|
| Tercel Sedan | ||
| Minimum Opening | 93-126 (34-52) | |
| Partial Opening | 138-180 (59-82) | |
| Maximum Opening | Above 192 (89) | |
HOT IDLE COMPENSATOR OPERATING TEMPERATURES