My post about holes in the cap are for visual confirmation of the phasing of the rotor lug to the terminals in the distributor cap.
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My post about holes in the cap are for visual confirmation of the phasing of the rotor lug to the terminals in the distributor cap.
Internal (underside) intake manifold vacuum leaks can usually be verified by sealing the valve cover breather port (tape) on one valve cover and feeling for vacuum at the other valve cover port (usually where the PCV is located), lightly place finger over the open hole while the motor is idling. Any pull or vacuum felt is usually from the leak on the underside of the manifold.