oldsmobile Workshop Repair Guides

Oldsmobile Workshop Service and Repair Manuals

Vacuum Spark Delay Valve > < Distributor Vacuum Modulator Valve (DVMV)|Page 718
Page 1
background image

Distributor Vacuum Control: Testing and Inspection
Vacuum Modulator Valve

1.

Block drive wheels, apply parking brake and place transmission in park.

2.

Start engine and run at slow idle.

3.

Connect vacuum gauge to hose leading to VMV port ``M.'' If reading is less than 14 inches Hg, check vacuum pump, VRV, solenoid and
connecting hoses.

4.

Reconnect hose to VMV port ``M'' and connect gauge to VMV port ``D.''

5.

Gauge should read 13 inches Hg. If not, VMV is defective.

Vacuum Spark Delay Valve > < Distributor Vacuum Modulator Valve (DVMV)|Page 718