Air Injection: Testing and Inspection

Fig. 42 Testing AI System - Cold Engine:

Fig. 43 Testing AI System - Engine Deceleration:

1. Visually inspect air injection hoses, fittings and components for damage and wear. Repair as needed.
2. Inspect wiring and electrical connectors to sensors, control valves and computer. Repair as needed.
3. Ensure engine is cold (coolant temperature below 43°F), then disconnect air bypass hose from air cleaner.
4. Start engine and observe air flow from bypass hose. Air should be continuously discharged from hose. Fig. 42
5. Warm engine to above 64° F. No air should be discharged from the bypass hose.
6. Run engine at 3000 RPM while observing air flow from bypass hose. Air should be discharged from the bypass hose.
7. Momentarily race engine, then release throttle linkage. Air should be discharged from bypass hose for 1 - 3 seconds after throttle is released. Fig. 43

Fig. 45 Testing AI VTV:

Fig. 46 Connecting Vacuum Gauge:

8. Check the vacuum transmitter valve (VTV) by disconnecting the hose between the VTV and the intake manifold at the VTV side. Check that air is discharged from the air bypass hose within 7 - 14 seconds. Fig. 45
9. Check the vacuum switching valve (VSV) by disconnecting the hose between the VSV and ASV at the VSV side. Connect a vacuum guage to the VSV port, Fig. 46. Increase the engine speed to 4,800 rpm and check that the vacuum gauge indicates zero.

Fig. 47 Testing AI Vacuum Switch:

10. Pinch the hose between the vacuum switch and air pipe, Fig. 47. Increase the engine speed to 4,800 rpm and check that the vacuum gauge indicates manifold vacuum. Disconnect vacuum guage and reconnect VSV hose.
11. If system fails to perform as outlined, test components individually.