DESCRIPTION
System consists of jet air control valve (which is an integral part of the carburetor) and thermo valve which is controlled by coolant temperature.
Purpose of the system is to help decrease hydrocarbon (HC) and carbon monoxide (CO) emissions during engine warm-up while choke is operating.
OPERATION
Carburetor vacuum opens control valve allowing additional airflow into the jet air passage. Air/fuel ratio is properly maintained to eliminate an over rich condition during engine warm-up.
Function of thermo valve is to stop operation of the jet air control valve when coolant temperature is below or above pre-set value. Thermo valve also works in conjunction with and as part of the EGR system.
Scheme 50
TESTING
Note. Testing information not available.