Evaporative Emissions System: Testing and Inspection

CHECKING SYSTEM





1. Disconnect the vacuum hose (red stripe) from the throttle body, and connect a vacuum pump to the vacuum hose.
2. Check the following points when the engine coolant temperature is 60° C (140° F) or below (cold) and when engine coolant temperature is 70° C (158° F) or higher (warm).





- When engine is cold





- When engine is warm

Purge Port Vacuum Curve:

CHECKING PURGE PORT VACUUM

NOTE: Verify engine coolant temperature is 80 - 95° C (176 - 205° F)





1. Disconnect the vacuum hose from the intake manifold purge hose nipple and connect a hand vacuum pump to the nipple.
2. Start the engine and check to see that, after raising the engine speed by racing the engine, vacuum remains fairly constant.

NOTE: If there is no vacuum created, it is possible that the intake manifold port may be clogged and require cleaning.