Evaporation Emission (EVAP) Canister Purge Valve Diagnosis (1.8L)

1. Remove EVAP canister. Install a plug into port No. 5. See Fig 1. While holding port No. 2 closed, blow into port No. 1. Air should pass from port No. 4. While holding ports No. 2 and No. 4 closed, blow into port No. 1. Air should NOT pass from port No. 3.
2. Connect a hand-held vacuum/pressure pump to port No. 2. Apply 1.01 in. Hg vacuum. Plug port No. 3 and check that vacuum does NOT decrease. Unplug port No. 3 and check that vacuum does decrease.
3. Remove hand-held vacuum/pressure pump from port No. 2 and connect to port No. 1. Apply 1.01 in. Hg vacuum. Plug port No. 3 and check that air flows into port No. 2. If operation is not as specified, replace EVAP canister purge valve.

Fig 1: Identifying EVAP Canister Purge Valve Ports (1.8L)

Courtesy of GENERAL MOTORS CORP.