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On Board Refueling Vapor Recovery (ORVR) Circuit Check

On Board Refueling Vapor Recovery (ORVR) Circuit Check

System Description






From the beginning of refueling, the air and vapor inside the fuel tank go through refueling EVAP vapor cut valve and EVAP/ORVR line to the EVAP canister. The vapor is absorbed by the EVAP canister and the air is released to the atmosphere.
When the refueling has reached the full level of the fuel tank, the refueling EVAP vapor cut valve is closed and refueling is stopped because of auto shut-off. The vapor which was absorbed by the EVAP canister is purged during driving.

WARNING:
When conducting inspections below, always observe the following:
- Put a "CAUTION: FLAMMABLE" sign in workshop.
- Never smoke while servicing fuel system. Keep open flames and sparks away from work area.
- Always furnish the workshop with a CO2 fire extinguisher.


CAUTION:
- Before removing fuel line parts, carry out the following procedures:
a. Put drained fuel in an explosion-proof container and put lid on securely.
b. Release fuel pressure from fuel line. Refer to [Fuel Pressure Check:VQ40DE]. Testing and Inspection
c. Disconnect battery negative cable.

- Always replace O-ring when the fuel gauge retainer is removed.
- Never kink or twist hose and tube when they are installed.
- Never tighten hose and clamps excessively to avoid damaging hoses.
- After installation, run engine and check for fuel leaks at connection.
- Never attempt to top off the fuel tank after the fuel pump nozzle shuts off automatically.
Continued refueling may cause fuel overflow, resulting in fuel spray and possibly a fire.


Diagnosis Procedure

SYMPTOM: FUEL ODOR FROM EVAP CANISTER IS STRONG.

Step 1-6:






SYMPTOM: CANNOT REFUEL/FUEL ODOR FROM THE FUEL FILLER OPENING IS STRONG WHILE REFUELING.

Step 1-7:




Step 8-11:






Component Inspection

REFUELING EVAP VAPOR CUT VALVE

With SDT
1. Remove fuel tank.
2. Drain fuel from the tank as follows
a. Remove fuel feed hose located on the fuel gauge retainer.
b. Connect a spare fuel hose, one side to fuel gauge retainer where the hose was removed and the other side to a fuel container.
c. Drain fuel using "FUEL PUMP RELAY" in "Active test" mode with SDT.

3. Check refueling EVAP vapor cut valve for being stuck to close as follows.
Blow air into the refueling EVAP vapor cut valve (from the end of EVAP/ORVR line hose), and check that the air flows freely into the tank.

4. Check refueling EVAP vapor cut valve for being stuck to open as follows.
a. Connect vacuum pump to hose end.
b. Remove fuel gauge retainer with fuel gauge unit.
Always replace O-ring with new one.

c. Turn fuel tank upside down.
d. Apply vacuum pressure to hose end [-13.3 kPa (-100 mmHg, -3.94 inHg)] with fuel gauge retainer remaining open and check that the pressure is applicable.






Without SDT
1. Remove fuel tank.
2. Drain fuel from the tank as follows:
a. Remove fuel gauge retainer.
b. Drain fuel from the tank using a handy pump into a fuel container.

3. Check refueling EVAP vapor cut valve for being stuck to close as follows.
Blow air into the refueling EVAP vapor cut valve (from the end of EVAP/ORVR line hose), and check that the air flows freely into the tank.

4. Check refueling EVAP vapor cut valve for being stuck to open as follows.
a. Connect vacuum pump to hose end.
b. Remove fuel gauge retainer with fuel gauge unit.
Always replace O-ring with new one.

c. Turn fuel tank upside down.
d. Apply vacuum pressure to hose end [-13.3 kPa (-100 mmHg, -3.94 inHg)] with fuel gauge retainer remaining open and check that the pressure is applicable.






DRAIN FILTER
1. Check visually for insect nests in the drain filter air inlet.
2. Check visually for cracks or flaws in the appearance.
3. Check visually for cracks or flaws in the hose.
4. Blow air into port A and check that it flows freely out of port B.






5. Block port B.
6. Blow air into port A and check that there is no leakage.
7. If NG, replace drain filter.