Evaporative Emissions System: Testing and Inspection
INSPECTION1. INSPECT LINES AND CONNECTORS
Visually check hoses for loose connections, bends or damage.
If necessary, repair or replace the hoses.
2. INSPECT FUEL TANK FILLER PIPE
Visually check the fuel tank filler pipe for deformation, cracks or fuel leak.
If necessary, repair or replace the fuel tank filler pipe.
3. INSPECT FUEL TANK CAP
Visually check if the cap and/or gasket are deformed or damaged.
If necessary, repair or replace the cap and/or gasket.
4. INSPECT EVAP SYSTEM LINE
a. Warm up the engine to the normal operating temperature, then stop the engine.
b. Install a vacuum gauge (EVAP control system test equipment vacuum gauge) to the EVAP service port on the purge line.
c. When using the hand-held tester:
Forced driving of the VSV for the EVAP.
1. Connect the hand-held tester to the DLC3.
2. Start the engine.
3. Push the hand-held tester main switch ON.
4. Use the hand-held tester ACTIVE TEST to operate the VSV for EVAP.
d. When not using the hand-held tester:
Forced driving of the VSV for the EVAP.
1. Disconnect the VSV connector for the EVAP.
2. Connect the battery's positive (+) and negative (-) to the VSV terminals for the EVAP.
3. Start the engine.
e. Check the vacuum at idle.
Vacuum: 0.368 to 3.678 in.Hg (5 to 50 in.Aq) should be maintained for more than 5 seconds
HINT: If the vacuum does not change, there is a possibility that the hose connecting the VSV to the service port may be loose or blocked, or the VSV may have a malfunction.
f. When using the hand-held tester:
Forced driving of the VSV for EVAP.
1. Stop the engine.
2. Disconnect the hand-held tester from the DLC3.
g. When not using the hand-held tester: Forced driving of the VSV for EVAP.
1. Stop the engine.
2. Disconnect the battery's positive (+) and negative (-) leads 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. Using a hose clipper or similar instrument, pinch the air drain hose at the position shown in the illustration to close the hose.
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. Apply pressure (13.5 to 15.5 in.Aq) from the EVAP service port.
Pressure: 2 minutes after the pressure is applied, the gauge should be over 7.7 to 8.8 in.Aq.
HINT: If no more pressure can be applied, the hose connecting among the VSV, canister and fuel tank may be slipped off or the VSV may be open.
3. Check if the pressure decreases when the fuel tank cap is removed while applying pressure.
HINT: If the pressure does not decrease when the fuel tank cap is removed, there is a possibility that the hose connecting the service port to the fuel tank may be blocked.
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 connections of the hoses and pipes.
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 amount of fuel in the fuel tank. When the fuel tank is full, the float valve of the fill check valve is closed and no air can pass through.
1. If air can flow freely from the purge port through to the EVAP line hose, the fuel cutoff valve and fill check valve are operating normally. Go to step (d).
2. If air cannot flow freely from the purge port through to the EVAP line hose, disconnect the vent line hose and EVAP line hose and check if they are clogged or not. If clogged, replace as necessary.
3. If the vent line hose and EVAP line hose are operating normally and air still cannot flow freely from the purge port through to the EVAP line hose, replace the fuel cutoff valve and fill check valve.
d. Reconnect the purge line hose and EVAP line hose to the charcoal canister.
7. CHECK AIR INLET LINE HOSE
a. Disconnect the air inlet line hose from the charcoal canister.
b. Check that there is ventilation in the air inlet line.
If the air inlet line is clogged, repair or replace the hose.
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 the charcoal canister.
1. Push the connector deeply.
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.
HINT: Be sure to check the areas indicated by the arrow marks. These areas are especially prone to cracking.
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. 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 mmHg, 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