Hot Idle Compensator (Non Comp. Controlled): Testing and Inspection

Basic systems consist of an HIC valve, a check valve (in most cases), and an intake manifold tap. The HIC valve admits a controlled amount of air to the intake manifold to maintain proper air/fuel mixture ratio at high temperature idle.

Testing


Do not allow water to enter HIC valve during testing, or damage to valve will result. The following temperatures are approximates, a slight variation between actual temperature and temperature range described is acceptable. For example, a in air cleaner temperature of 80°F, (described temperature at 84-126°F) is acceptable. With temperature in air cleaner at 84-126°F, HIC atmospheric port open, HIC valve vacuum port opening (minimum), the HIC system will be off. With temperature in air cleaner at 138-180°F, HIC valve atmospheric port open, HIC valve vacuum port opening (partial), the HIC system will be on. With temperature in air cleaner above 192°F, HIC valve atmospheric port open, HIC valve vacuum port opening (maximum), the HIC system will be on.
1. Cover atmospheric port of HIC valve. Orally blow air into HAI port. Air should flow from the intake manifold tap port.
2. Orally blow air into the manifold tap port (no ports covered). Air should not flow out from the HAI port.
3. At low temperature point, cover manifold tap port. Orally blow air into the HAI port. No air should flow from the atmospheric port.
4. Heat thermo bulb end of HIC valve in water. Cover intake manifold tap port. Orally blow air into HAI port. At temperatures above low temperature point, air should flow from atmospheric port.