- Fuel Tank (See Fuel Tank Removal in the Fuel System chapter)
- Fuel Hose (See Fuel Hose Replacement)
- Connect the following parts temporary.
- Fuel Pump Lead Connector [A]
- Fuel Level Sensor Lead Connector [B]
- Extension Tube [C]
Special Tool - Extension Tube: 57001-1578
- Pull the air switching valve hose [D] out of the air cleaner housing.
- Start the engine and run it at idle speed.
- Plug [A] the air switching valve hose end with your finger and feel vacuum pulsing in the hose.
If there is no vacuum pulsation, check the hose line for leak. If there is no leak, check the air switching valve (See Air Switching Valve Unit Test in the Electrical System chapter) or air suction valve (See Air Suction Valve Inspection in the Engine Top End chapter).
