Evaporative Emissions System: Testing and Inspection

FUNCTIONAL CHECK:

Fuel Tank Pressure Control Valve:

Fuel Tank Pressure Control Valve
With hand vacuum pump, apply approximately 38 cm Hg (15" Hg) to the control vacuum tube. After ten seconds, there should be at least 13 cm Hg (5" Hg) vacuum remaining. If after 10 seconds there is less than specified vacuum, replace the valve.

With 38 cm Hg (15" Hg) applied to control vacuum tube, attach a short piece of hose to the valves tank tube side. Blow into the tube. You should feel air pass through the valve. If not, replace the valve.

Inspect
Ensure all connections and vacuum lines are tight and free of cracks, damage or restrictions. Visually check vapor canister for cracks and/or damage. Check that fuel filler cap is correct for application and in good condition.

For canister purge valve test procedure, Chart C-3 Canister Purge Check