Evaporative Emissions System: Testing and Inspection

SYSTEM

1. Check vacuum hoses for proper routing, poor connections, clogs or leaks, repairing or replacing as necessary.
2. Warm engine to operating temperature and run at idle.
3. Disconnect vacuum hose from No. 1 purge control valve and connect tool 499200750A or equivalent to hose.
4. Increase engine speed to above 2500 RPM and ensure gage shows more than 5.9 inches Hg vacuum.
5. If vacuum is not correct, check water thermo valve.
6. Reconnect hose to No. 1 purge control valve.
7. Disconnect centermost hose from canister and place finger over end of hose.
8. Accelerate engine rapidly and ensure vacuum is felt above 1500 RPM.
9. Reconnect hose to canister.
10. Disconnect remaining hose from canister and place finger over end of hose.
11. If vacuum is not felt, check vacuum line between canister and dynamic chamber for blockage.
12. Disconnect evaporation hose from evaporation pipe.
13. Connect vacuum pump to evaporation pipe.
14. Operate vacuum pump.
15. If vacuum is held, check evaporation pipe for clogging.

EVAPORATIVE LINE

Fig. 30 Checking evaporative line using ``U'' tube pressure gauge:

Exc. 323, 626, 929, B2000, B2600, 1986---88 RX-7 & 1987---88 B2200

1. Disconnect evaporative hose from canister.
2. Using a suitable ``U'' tube pressure gauge, Fig. 30, connect disconnected hose to ``U'' tube pressure gauge.
3. Gradually apply low pressure compressed air into ``U'' tube for 5 minutes. If water level drops, evaporative line is in proper condition. If water level remains the same, replace evaporative line.