Air Diverter Valve: Testing and Inspection

NOTE: If engine is at operating temperature, temporarily connect manifold vacuum to the valve during test, since the AGE/CTO switch directs manifold vacuum to the air control valve circuit.

1. Start engine and run at idle.
2. Check diverter valve vents. Little or no air should flow from vents.
3. Accelerate engine to 2,000-3,000 rpm and rapidly close throttle. A strong flow of air should flow from the diverter valve vents for about 5 seconds. The high air flow diverter valve used on some engines should vent for about 3 seconds. If air does not vent, or if back fire occurs, make sure that vacuum hose is not leaking.

NOTE: The diverter valve diverts air pump output when a vacuum of 20 inches Hg or more is applied to diaphragm. The diverter valve diverts air when the pump output exceeds 5 psi.

4. Slowly accelerate engine to 3,500 rpm. Between 2,500-3,500 rpm, air should begin to flow from the diverter vents.