Century Estate Wagon L4-151 2.5L VIN R TBI (1987)
![background image](/buick/century_estate_wagon/l4-151_2.5l_vin_r_tbi/Page-176001.png)
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.