Vacuum Advance
Checking Vacuum Advance:
1. Remove distributor cap.
2. Disconnect vacuum hoses and connect vacuum pump gauge to outside diaphragm.
3. Apply about 400 mmHg (15 in.Hg) vacuum and release it, then check to make sure that pick up coil moves with base plate smoothly.
4. Repeat same procedure to inside diaphragm.
5. If any abnormality is found, replace vacuum controller or distributor housing assembly.