Excel L4-1468cc 1.5L SOHC (8 VALVE) (1986)
Thermo Valve, EGR: Description and Operation
Connected in series in the EGR vacuum signal line, this valve senses coolant temperature in the intake manifold. When coolant temperatures are below
specified values, the thermo valve blocks the vacuum signal to the EGR control valve, preventing EGR flow and improving cold engine driveability.
When coolant temperature is at or above specified values, the thermo valve opens the vacuum signal to the control valve, allowing normal EGR
operation to take place.