Evaporative Emissions System: Testing and Inspection
Fig. 9 Checking solenoid valve:
SOLENOID VALVE 1 & 2 CHECK
Disconnect hoses from ports B and C on no. 1 three-way solenoid valve, Fig. 9. Apply air through port A and confirm that it exits through port C. Apply 12 volts to solenoid valve and confirm that when air is applied to port A, it exits through port B, Fig. 9.
Fig. 10 Evaporative Emission Control system wiring check:
Fig. 11 Checking solenoid valve:
WIRING CHECK
1. With ignition switch ON, check for 12 volts at no. 1 three-way solenoid valve yellow/green terminal, Fig. 10. If 12 volts are not present, check circuit for opens, shorts, failed connectors or components.
2. With ignition switch ON, check for 12 volts at ECA 2P terminal, Fig. 11. If 12 volts are not present, check circuit for opens, shorts, failed connectors or components.
Fig. 12 Checking no. 2 purge control valve:
Fig. 13 Checking no. 2 purge control valve:
Fig. 14 Checking no. 3 purge control valve:
PURGE CONTROL VALVE CHECK
1. Check that air does not flow through port A, then apply 4.4 inches Hg vacuum to purge control valve, Fig. 12. Air should not flow through port A with vacuum applied.
2. Disconnect vacuum tube A from no. 2 purge control valve, Fig. 13. Apply pressure and vacuum to purge control valve, and confirm that air flows through purge control valve. If not, replace canister.
3. Remove purge control valve, Fig. 14, and apply 4 inches Hg vacuum to valve. Air should flow from port A to B. If not, replace no. 3 purge control valve.
Fig. 15 Checking rollover vent valve:
Fig. 16 Checking rollover vent valve:
ROLLOVER VENT VALVE
1. Remove valve, then connect an air pressure gauge to fuel tank passage, Fig. 15, and apply .75 PSI pressure to port A. With valve in vertical position, check that valve opens at specified pressure. If not, replace valve.
2. Connect pressure gauge to atmosphere passage, Fig. 16, and apply 1.0 PSI to port B. With valve in vertical position, check that valve opens at specified pressure. If not, replace valve.