Distributor Vacuum Advance

Fig. 36 Testing Vacuum Advance:

1. Remove the cap and rotor from the distributor.
2. Remove both vacuum hoses from the advance diaphragms. Fig. 36
3. Test each diaphragm by applying vacuum to the vacuum ports with a handheld vacuum pump.
4. Check that the pick-up plate inside the distributor moves in accordance with the applied vacuum.
5. If a problem is found, replace vacuum advance diaphragm or repair distributor.
6. Reinstall the distributor cap and rotor. Reconnect vacuum hoses.