Distributor Assembly Ventilation System Checking
The ventilation system vacuum harness assembly (29), connected to the air intake duct (30), the distributor assembly (1) and the air intake manifold (31), provides ventilation to the distributor assembly (1), thus preventing moisture build-up and possible ignition system failure. A check valve at the air intake duct connection insures one-way flow through the distributor assembly (1) to the air intake manifold (31). See Figure for correct orientation.
The ventilation system vacuum harness assembly (29) connects to the air intake duct (30) and the air intake manifold (31) with vacuum fittings. It attaches to the distributor assembly (1) at two places with separately sized connectors.
In the case of ignition system failure, check vacuum harness assembly (29) for proper hook-up and/or kinks. If okay, check the ventilation system for a possible restriction before removing the distributor assembly (1).
Disconnect the vacuum harness assembly (29) at the air intake duct (30) and check for vacuum using a vacuum gauge. The gauge needle should slowly move towards manifold vacuum. If no vacuum is present, replace the vacuum harness assembly (29). Once is has been determined that the ventilation system vacuum harness assembly is functioning properly, disconnect the vacuum gauge and reconnect the vacuum hose to the air intake duct. Running the engine with manifold vacuum present in the distributor may lead to engine misfire.