Distributor Advance Unit: Testing and Inspection

1. Remove distributor cap and disconnect vacuum hoses from advance unit.
2. Connect a suitable vacuum pump to diaphragm A (inside port) of advance unit.
3. Apply approximately 20 inches Hg vacuum to diaphragm and observe movement of stator.
4. Stator should rotate counterclockwise (clockwise on Legend models) and should hold in this position. If stator does not rotate, or fails to hold in position, replace advance unit.
5. Release vacuum and again observe movement of stator. Stator should return to original position. If not, repair or replace advance unit as necessary.
6. Repeat steps 1 through 5 for diaphragm B (outer port).