THERMACTOR Air Control

This system is similar to the standard Thermactor air pump system, but it also adds a second air control valve (in addition to the by-pass valve), and a second exhaust check valve. Other system components include the air pump, Ported Vacuum Switch (PVS) and the Temperature Vacuum Switch (TVS).

Above 125°F coolant temperature, air pump air is routed to the mixing chamber of the dual catalytic converter. Below 125°F coolant temperature, the PVS applies vacuum to the air control valve which directs air pump air to the exhaust manifold to decrease HC and CO during warmup.

A catalyst protection feature is used when the TVS (on the air cleaner) senses inlet air temperatures below 49°F. This causes the by-pass valve to dump air pump air to the atmosphere (not to the exhaust manifold or converter mixing chamber).