What does the vaccum modulator valve do? just curious

There is a vacuum modulator and a vacuum control valve, but not a vacuum modulator valve.

The vacuum control valve on the IP simulates manifold vacuum as if the engine had an air throttle. It functions as an engine load sensor, more load = less vacuum, but it's more accurately a throttle position sensor. The modulator translates this vacuum signal into plunger motion so shift quality is maintained regardless of engine load.

Sixto
87 300D^2