Pinpoint Test D: Hiss When Opening Fuel Cap

WARNING: This page is about a different car, the 2004 Mercury Mountaineer and 2004 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.

D1 TEST FOR EVAP CANISTER, CANISTER VENT SOLENOID AND CANISTER VENT HOSE ASSEMBLY BLOCKAGE
- Connect the Evaporative Emission System Tester to the fuel filler cap.
- Pressurize the EVAP system to 3.48 kPa (14 inches H² O).
- Does the pressure drop immediately?
Yes

The EVAP system has passed the EVAP canister and bracket assembly blockage test. GO to D6

No

For vehicles equipped with a canister vent hose assembly, GO to D2.

For vehicles equipped with a canister vent solenoid, GO to D3. For all others, GO to D4.
D2 TEST FOR CANISTER VENT HOSE ASSEMBLY BLOCKAGE
- Disconnect the EVAP canister vent hose assembly from the EVAP canister.
- Connect the Evaporative Emission System Tester to the fuel filler pipe.
- Pressurize the EVAP system to 3.48 kPa (14 inches H² O).
- Does the pressure drop immediately?
Yes

INSTALL a new EVAP canister vent solenoid vent hose assembly. CARRY OUT the evaporative emission system leak test. REFER to EVAPORATIVE EMISSION SYSTEM LEAK TEST . If the system passes the leak test, CARRY OUT the evaporative emission repair verification drive cycle. Refer to EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE .

No

GO to D4.
D3 TEST FOR CANISTER VENT SOLENOID BLOCKAGE
- Remove the canister vent solenoid from the EVAP canister.
- Connect the Evaporative Emission System Tester to the fuel filler pipe.
- Pressurize the EVAP system to 3.48 kPa (14 inches H² O).
- Does the pressure drop immediately?
Yes

INSTALL a new canister vent solenoid. REFER to FUEL VAPOR VENT VALVE . CARRY OUT the evaporative emission system leak test. REFER to EVAPORATIVE EMISSION SYSTEM LEAK TEST . If the system passes the leak test, CARRY OUT the evaporative emission repair verification drive cycle. Refer to EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE .

No

GO to D4.
D4 TEST FOR EVAP CANISTER BLOCKAGE
- Disconnect the EVAP canister tube (from the fuel tank) at the F-fitting from the EVAP canister.
- Connect the Evaporative Emission System Tester to the fuel filler pipe.
- Pressurize the EVAP system to 3.48 kPa (14 inches H² O).
- Does the pressure drop immediately?
Yes

INSTALL a new EVAP canister. Refer to EVAPORATIVE EMISSION CANISTER AND PURGE VALVE - 4.0L SOHC EARLY BUILD or EVAPORATIVE EMISSION CANISTER AND PURGE VALVE - 4.6L AND 4.0L SOHC LATE BUILD . CARRY OUT the evaporative emission system leak test. REFER to EVAPORATIVE EMISSION SYSTEM LEAK TEST . If the system passes the leak test, CARRY OUT an evaporative emissions repair verification drive cycle. Refer to EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE .

No

GO to D5.
D5 TEST FOR EVAP CANISTER TUBE OR FUEL VAPOR VENT VALVE ASSEMBLY BLOCKAGE
- Disconnect the fuel vapor vent valve assembly from the EVAP canister tube
- Connect the Evaporative Emission System Tester to the fuel filler pipe.
- Pressurize the EVAP system to 3.48 kPa (14 inches H² O).
- Does the pressure drop immediately?
Yes

INSTALL a new EVAP canister tube and/or fuel vapor tube(s) between the fuel tank and the EVAP canister and bracket assembly. CARRY OUT the evaporative emission system leak test. REFER to EVAPORATIVE EMISSION SYSTEM LEAK TEST . If the system passes the leak test, CARRY OUT the evaporative emission repair verification drive cycle. Refer to EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE .

No

INSTALL a new fuel tank. Refer to FUEL TANK AND FILLER PIPE - 4.0L SOHC EARLY BUILD or FUEL TANK AND FILLER PIPE - 4.6L AND 4.0L SOHC LATE BUILD . CARRY OUT the evaporative emission system leak test. REFER to EVAPORATIVE EMISSION SYSTEM LEAK TEST . If the system passes the leak test, CARRY out the evaporative emission repair verification drive cycle. Refer to EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE .
D6 TEST FOR BLOCKAGE BETWEEN THE EVAP CANISTER PURGE VALVE AND THE FUEL TANK
- Remove the fuel vapor hose (from the fuel tank) at the EVAP canister purge valve.
- Connect the Evaporative Emission System Tester to the fuel filler pipe.
- Key in ON position
- For vehicles equipped with a canister vent solenoid, close the canister vent solenoid. Refer to CANISTER VENT SOLENOID CLOSING PROCEDURE .
- For vehicles without a canister vent solenoid, plug the canister vent hose assembly or plug the canister vent cap.
- Pressurize the EVAP system to 3.48 kPa (14 inches H² O).
- Does the pressure drop immediately?
Yes

The EVAP system has passed all the blockage tests.

RECONNECT all components.

For vehicles equipped with a canister vent solenoid, CARRY OUT the evaporative emission system leak test. REFER to EVAPORATIVE EMISSION SYSTEM LEAK TEST . If the system passes the leak test, CARRY OUT the evaporative emission repair verification drive cycle. Refer to EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE .

For vehicles equipped without a canister vent solenoid, PLUG the canister vent hose assembly or the canister vent cap. CARRY OUT the evaporative emission system leak test. REFER to EVAPORATIVE EMISSION SYSTEM LEAK TEST . If the system passes the leak test, CARRY OUT the evaporative emission repair verification drive cycle. Refer to EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE .

No

INSTALL a new fuel vapor hose. CARRY OUT the evaporative emission system leak test. REFER to EVAPORATIVE EMISSION SYSTEM LEAK TEST . If the system passes the leak test, CARRY OUT the evaporative emission repair verification drive cycle. Refer to EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE .