System Quick Check

PROCEDURE
A quick check of the system can be made by pulling the end of the valve out of the valve cover and, with the engine idling, placing a finger over the end of the valve to block the air flow. A vacuum should be felt and the engine speed should drop approximately 50 rpm if the system is satisfactory. If there is no change in engine speed a clogged system is indicated. To isolate the problem, remove the valve from the hose.

If the ventilator hoses and carburetor passages are clear, a strong vacuum will be felt and the engine idle will change drastically or the engine will stall when the end of the hose is uncovered. If this occurs, the trouble is in the valve. If the engine continues to idle approximately as it did before the hose was uncovered, the hoses or carburetor passages are blocked.