System Check - Distributor Vent

Distibutor Vent:

Diagnostic Chart:

Legend

(1) Clean Air Supply Hose (from air intake duct)

(2) Vacuum Supply from Intake Manifold

(3) Check Valve

(4) Rocker Cover

(5) Vent System Harness

(6) Air Injection Reaction (AIR) Pump

(7) Check Valve Filter

(8) Air Intake Duct

(9) Distributor

CIRCUIT DESCRIPTION

The distributor is equipped with a fresh air vent system. When the engine is started, vacuum that the engine produces pulls fresh air in from the air intake duct. A constant supply of fresh air is needed within the distributor. An inoperative distributor vent system may cause premature distributor failure.

DIAGNOSTIC AIDS

If the check valve/filter or the check valve is installed backwards the system will not function. Verify flow direction is toward the manifold using a hand held vacuum pump at the check valve and the check valve/filter primer ports. Vacuum should hold in one direction and not the other. If vacuum holds or does not hold in both direction, for either component, that component is faulty.

TEST DESCRIPTION

Number(s) below refer to step number(s) on the diagnostic table.

2. Check for a blocked or restricted vacuum source.

5. Check for a blocked, restricted or collapsed hoses. Check the connections at the distributor cap for a blockage. Check for a faulty check valve or check valve/filter.

6. Check for damaged or leaking hoses or connections. Check the seal between the distributor cap and the distributor. Also, check the distributor cap for cracks or other damage.