Navajo 4WD V6-4.0L OHV (1991)
air/fuel mixture.
As the engine reaches operating temperature, the bimetal spring, connected with the valve plate to the shaft, begins to expand, this causes the valve to
open.
Exhaust now flows through the exhaust system instead of bypassing through the intake manifold.
During high engine rpm or load, the valve will open due to the imbalance of the valve plate, even if operating temperatures have not yet been reached.