Evaporative Emissions System: Testing and Inspection

Fig. 19 Evaporative emission control system.:

Fig. 7 Checking Voltage At Neutral/Inhibitor Switch Connector----113:

1. Warm engine to normal operating temperature and run at idle.
2. On non-turbo models, connect voltmeter to solenoid valve for No. 2 purge control valve BY terminal and ensure voltage is approximately 12 volts.
3. On turbo models, connect voltmeter to solenoid valve for No. 1 purge control valve YG terminal and ensure voltage is approximately 12 volts.
4. Disconnect vacuum hose from No. 1 purge control valve and place finger over hose opening.
5. Increase engine speed to approximately 2000 RPM and ensure air is not sucked in.
6. On vehicles w/manual transaxle, disconnect neutral switch electrical connector and connect a jumper wire to connector terminal female side Fig. 7.
7. On vehicles with automatic transaxle, disconnect inhibitor switch connector.
8. On turbo models, disconnect throttle sensor electrical connector, leaving vacuum hose attached.
9. On all models, ensure voltage at BY terminal (non-turbo) or YG terminal (turbo) is less than 1.5 volts.
10. Place finger over hose opening.
11. Increase engine speed to approximately 2000 RPM and ensure air is sucked in.
12. If operation is not satisfactory, check solenoid valve for No. 1 purge control valve, engine control unit 2P terminal, and No. 1 purge control valve.
13. Connect neutral or inhibitor switch connector.
14. Disconnect evaporation hose from evaporation pipe.
15. Connect vacuum pump to evaporation pipe.
16. Operate vacuum pump and ensure no vacuum is held.
17. If vacuum is held, check three-way check valve or evaporation pipe for blockage.