Skylark V6-173 2.8L VIN X 2-bbl (1984)
Distributor Vacuum Control: Description and Operation
Distributor Spark Vacuum Modulator Valve (DS-VMV)
This valve limits distributor spark vacuum to a calibrated value until ported vacuum applied to the control port of the DS-VMV is greater than the
calibration value. When ported vacuum is greater than the calibration value, the distributor spark vacuum is equal to the ported vacuum signal.
