Evaporative Emissions System: Testing and Inspection

Fig.47 - Checking Evaporative Line Using "U" Tube Pressure Gauge:

Checking Evaporative Line
1. Disconnect evaporative hose from canister.
2. Using a suitable "U" tube pressure gauge, Fig. 47 connect disconnected hose to "U" tube pressure gauge.
3. Gradually apply low 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.

Canister

Visually check canister for leaks. Tap canister and listen for any abnormal sounds, replace canister as required.

Fig.48 - Testing Check And Cut Valve:

Check & Cut Valve
1. Remove check and cut valve from engine.
2. Connect a suitable pressure gauge fuel inlet line and using a finger plug the other end.
3. Blow air through the valve, the valve should open with a pressure between 0.78-1.00 psi, (0.055-0.070 Kg/cm).
4. Remove pressure gauge and connect to atmosphere passage. Blow air through valve, if valve opens with a pressure between 0.14-0.71 psi, (0.01-0.05 Kg/cm), the valve is operating properly. If valve does not open to specified limit, replace check and cut valve.

Fig.49 - Checking Purge Control Valve:

Purge Control Valve
1. Disconnect vacuum hose from purge control valve. Disconnect and plug vacuum hose (B), Fig. 49.
2. Start and operate engine at idle.

Fig.50 - Using Tube (C) To Blow Air Into Purge Control Valve:

3. Connect a suitable tube (C), Fig. 50, to port (b) and blow air through tube. Ensure no air flows out through purge control valve.
4. Unplug vacuum hose (B) and connect to port (A). Blow air through vacuum hose, ensure air flows valve. If no air flow, replace valve.

Fig.51 - Checking No.2 Purge Control Valve:

No. 2 Purge Control Valve
1. Disconnect vacuum hose (A), Fig. 51, from purge control valve. Disconnect vacuum hose (B) from No. 2 purge control valve.
2. Blow air through vacuum hose (A) and ensure air does not flow from port (a).
3. Start and increase engine speed to 2000 RPM. Blow air through vacuum hose (A) and through No. 2 purge control valve. Ensure air flows out port (a). If no air flow, replace No.2 purge control valve.

Air Vent Solenoid Valve
1. Visually check air vent hose for cracks, replace hose if necessary.
2. Disconnect air vent hose from canister and blow air through air vent solenoid valve.
3. Switch ignition "ON" and blow air through air vent hose. Ensure air does not flow from air vent solenoid valve. If air flows, replace valve.