323 L4-1600 1597cc (1986)
Vacuum Advance Diaphragm: Testing and Inspection
Carburetor
1.
Warm up the engine fully.
2.
Make sure that the idling speed and ignition timing are within specifications.
IGNITION TIMING: 2° BTDC
IDLE SPEED: 850 rpm
Fig. 13 Disabling vacuum advance
3.
Remove the vacuum hose from the distributor vacuum control unit and plug the hose Fig. 13.
Fig. 14 Centrifugal spark advance curve
4.
While gradually increasing engine rpm, check changes in ignition timing with a timing light Fig. 14.
Excessive advance: Governor spring is fatigued (If the governor spring is broken, the initial advance is very quick and high).
