System Operational Test

Purge System Test:

1. Disconnect the purge air hose from the intake hose, and plug the air intake hose. connect a hand vacuum pump to the hose.
2. While the engine is cold (coolant temperature less than 140° F or 60° C) allow the engine to idle and apply 14.8 in. Hg (375 mm Hg) of vacuum.
a. If vacuum holds, proceed to next step.
b. If vacuum does not hold, check vacuum hoses, fitings and routing integrity. If no faults are found, proceed to PURGE CONTROL SOLENOID INSPECTION.
3. Increase engine speed to 3,000 rpm, apply 14.8 in. Hg (375 mm Hg) of vacuum.
a. If vacuum holds, proceed to next step.
b. If vacuum does not hold, check vacuum hoses, fitings and routing integrity. If no faults are found, proceed to PURGE CONTROL SOLENOID INSPECTION.
4. Allow the engine to warm up (engine coolant temperature greater than 158° F or 70° C ).
5. With the engine operating at idle apply 14.8 in. Hg (375 mm Hg) of vacuum.
a. If vacuum holds, proceed to next step.
b. If vacuum does not hold, check vacuum hoses, fitings and routing integrity. If no faults are found, proceed to PURGE CONTROL SOLENOID INSPECTION.
6. Within three minutes of engine start increase engine speed to 3,000 rpm and apply vacuum.
a. If vacuum does not hold, proceed to next step.
b. If vacuum does hold, proceed to PURGE CONTROL SOLENOID INSPECTION.

Note: The solenoid is controlled by the ECM. If the solenoid tests O.K., See PURGE CONTROL SOLENOID VALVE.

7. After more than three minutes have elapsed since engine start increase engine speed to 3,000 rpm, apply 14.8 in. Hg (375 mm Hg) and verify that vacuum is held momentarily and then leaks. (Note! Vacuum will leak continuously if the test is being performed at elevations greater than 2,200 m (7,200 ft.) or intake air temperature is greater than 122° F (50° C).