Chevrolet Chevette/1000 1976-1988 Repair Guide

Controlled Combustion System



The Controlled Combustion System (CCS) increases combustion efficiency by means of leaner carburetor mixtures and revised distributor calibration. Also, a thermostatically-controlled damper in the air cleaner snorkel maintains warm air intake to the carburetor to optimize fuel vaporization.

An air intake duct routes air from the radiator support to the air cleaner snorkel, then to the air cleaner. Air temperature is automatically controlled by a thermostatic damper inside the air cleaner snorkel. The damper selects warm air from the exhaust manifold heat stove when air temperature is below 50°F (10°C). When air temperature is above 110°F (43°C), the damper selects outside air from the air intake duct.

When replacing the air cleaner, remove the air cleaner from the air intake snorkel and the carburetor and throw it away. Check the carburetor air horn gasket and replace it if damaged or cracked, and install a new air cleaner.