1. Follow "BEFORE SERVICE PRECAUTION" before performing any work operations to prevent fuel from spilling from the fuel system. (See BEFORE SERVICE PRECAUTION [L8, LF].)
2. Remove the battery cover.
3. Disconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [L8, LF].)
4. Remove the fuel tank with the fuel pump unit. (See FUEL TANK REMOVAL/INSTALLATION [L8, LF].)
5. Perform the following procedure to verify the fuel tank airtightness.
6. Plug the fuel pump unit pipe and port B.
7. Level the fuel tank.
8. Apply a pressure of 3 kPa {23 mmHg, 0.9 inHg} to port C and wait for a while.
9. With the pressure still applied, verify that there is airflow from port A and the pressure is 0- 3 kPa {0-22 mmHg, 0- 0.8 inHg}.
10. Apply a pressure of -0.5 kPa {-3.8 mmHg, -0.1 inHg} to port C and wait for a while.
11. With the pressure still applied, verify that there is airflow from port A and the pressure is -0.5- 0 kPa {-3.8- 0 mmHg, -0.2- 0 inHg}.
12. Apply a pressure of 3 kPa {23 mmHg, 0.9 inHg} to port C and wait for a while.
13. With the pressure still applied, verify that there is no airflow from port A.