Evaporative Emissions System: Testing and Inspection
INSPECTION1. INSPECT LINES AND CONNECTORS
Visually check for loose connections, sharp bends or damage.
2. INSPECT FUEL TANK FILLER PIPE
Visually check for deformation, cracks or fuel leak.
3. INSPECT FUEL TANK CAP
Visually check if the cap and/or gasket are deformed or damaged.
If necessary, repair or replace the cap.
4. INSPECT EVAP SYSTEM LINE
a. Warm up the engine and stop the engine.
Warm up the engine to the normal operating temperature.
b. Install a vacuum gauge (EVAP control system test equipment vacuum gauge) to the EVAP service port on the purge line.
c. When using hand-held tester:
Forced driving of the VSV for the EVAP
1. Connect a hand-held tester to the DLC3.
2. Start the engine.
3. Push the hand-held tester main switch ON.
4. Use the ACTIVE TEST mode on the hand-held tester to operate the VSV for the EVAP
d. When not using hand-held tester:
Forced driving of the VSV for the EVAP
1. Disconnect the VSV connector for the EVAP
2. Connect the positive (+) and negative (-) leads from the battery to the VSV terminals for the EVAP
3. Start the engine.
e. Check the vacuum at idle.
Vacuum: Maintain at 0.368 - 3.678 in.Hg (5 - 50 in.Aq) for over 5 seconds
HINT: If the vacuum does not change, there is a possibility that the hose connecting the VSV to the service port is loose or blocked, or the VSV malfunctions.
f. When using hand-held tester:
Forced driving of the VSV for the EVAP
1. Stop the engine.
2. Disconnect the hand-held tester from the DLC3.
g. When not using hand-held tester:
Forced driving of the VSV for the EVAP.
1. Stop the engine.
2. Disconnect the positive (+) and negative (-) leads from the battery and from the VSV terminals for the EVAP.
3. Connect the VSV connector for the EVAP
h. Disconnect the vacuum gauge from the EVAP service port on the purge line.
i. Connect a pressure gauge to the EVAP service port on the purge line.
j. Check the pressure.
1. Close the air drain hose at the marked position of the canister by pinching it with a hose clipper or similar instrument.
HINT: Insert the hose clipper through the clearance of the front engine under cover and pinch the yellow marked portion of the air drain hose.
2. Increase the pressure (13.5 - 15.5 in.Aq) from the EVAP service port.
Pressure: 2 minutes after the pressure is increased, the gauge should be over 7.7 - 8.8 in.Aq.
HINT: If no the more pressure can be applied, there is a possibility that the hose connecting the VSV - canister - fuel tank has slipped off or the VSV is open.
3. Check if the pressure decreases when the fuel tank cap is removed while increasing pressure.
HINT: If the pressure does not decrease when the filler cap is removed, there is a possibility that the hose connecting the service port to the fuel tank is blocked, etc.
k. Disconnect the pressure gauge from the EVAP service port on the purge line.
5. CHECK AIRTIGHTNESS IN FUEL TANK AND FILLER PIPE
a. Disconnect the EVAP line hose from the charcoal canister.
1. Pinch portion A.
2. Pull the connector out.
b. Pressurize the internal fuel tank at 4 kPa (41 gf/sq.cm, 0.58 psi).
c. Check that the internal pressure of the fuel tank can be maintained for 1 minute.
d. Check the connected portions of each hose and pipe.
e. Check the installed parts on the fuel tank.
If there is abnormality, replace the fuel tank and filler pipe.
f. Reconnect the EVAP line hose to the charcoal canister.
6. INSPECT FUEL CUTOFF VALVE AND FILL CHECK VALVE
a. Disconnect the purge line hose and EVAP line hose from the charcoal canister.
b. Disconnect the drain hose from the charcoal canister and plug the drain port with a cap.
c. Pressurize the purge port at 4 kPa (41 gf/sq.cm, 0.58 psi) and check that it is ventilated through the EVAP line hose.
HINT: It is necessary to check the fuel amount (volume) as the float valve of the till check valve is closed and has no ventilation in the condition that the fuel is full.
d. Check if there is anything stuck in the vent line hose and EVAP line hose.
If there is nothing stuck in them, replace the fuel cutoff valve and fill check valve.
e. Reconnect the purge line hose and EVAP line hose to the charcoal canister.
7. CHECK AIR INLET LINE
a. Disconnect the air inlet line hose from the charcoal canister.
b. Check that there is ventilation in the air inlet line.
c. Reconnect the air inlet line hose to the charcoal canister.
8. REMOVE CHARCOAL CANISTER ASSEMBLY
a. Remove the bolt, 3 nuts and protector from the body.
b. Disconnect the VSV connector.
c. Disconnect the purge line hose, EVAP line hose and air inlet line hose from the charcoal canister.
d. Disconnect the vent line hose from charcoal canister.
1. Push the connector deep inside.
2. Pinch portion A.
3. Pull out the connector.
e. Remove the 2 bolts and charcoal canister assembly.
9. INSPECT CHARCOAL CANISTER
a. Visually check the charcoal canister for cracks or damage.
b. Inspect the charcoal canister operation.
1. Plug the vent port with a cap.
2. While holding the purge port closed, blow air (1.76 kPa, 18 gf/sq.cm, 0.26 psi) into the EVAP port and check that air flows from the air drain port.
3. While holding the purge port and the air drain port closed, blow air (1.76 kPa, 18 gf/sq.cm, 0.26 psi) into the EVAP port and check that air does not flow from the air inlet port.
4. Apply vacuum (3.43 kpa, 25.7 mmHg, 1.01 in.Hg) to the purge port and check that the vacuum does not decrease when the air inlet port is closed. And then check that the vacuum decreases when the air inlet port is released.
5. With the air inlet port closed, apply vacuum (3.43 kpa, 25.7 mm Hg, 1.01 in.Hg) to the EVAP port and check that air flows into the purge port.
If there is a problem, replace the charcoal canister.
6. Remove the cap from the vent port.
10. INSPECT VSV FOR EVAP
11. INSPECT VSV FOR CCV
12. INSPECT VSV FOR PRESSURE SWITCHING VALVE
13. INSPECT VAPOR PRESSURE SENSOR
14. REINSTALL CHARCOAL CANISTER ASSEMBLY
15. REINSTALL PROTECTOR