Air Injection Control Valve: Testing and Inspection

NOTE:
This test should be performed only after the air pump, electro-valve control switch (on 504 models), oil thermoswitch (on 604 models), and the electro-valves have been checked for proper operation.

Procedure

1. Place shift lever in neutral or park position.

2. Start engine and check for vacuum at injection valve vacuum line. If vacuum is not present check system for correct routing and connections.

3. Disconnect intake manifold air supply hose from injection valve and plug hose.

4. With engine at idle, check for air flow from valve. If air flow is detected, replace valve.

5. Open and close throttle several times and check for air flow from valve. Each time throttle is released, a short burst of air should be detected at valve outlet. If not, replace valve.