Cold Start Spark Advance System: Operation

System provides carburetor vacuum to the distributor from the carburetor vacuum tap, through the DRCV, CSSA PVS, and the cooling PVS. When the coolant temperature is between 125°F and 235°F, vacuum reaches the distributor from the carburetor spark port through the SDV, CSSA PVS, and cooling PVS. When the engine coolant is above 235°F, manifold vacuum is applied to the distributor advance through the PVS.