On-Vehicle Inspection

REMOVE ENGINE COVER
Remove the 4 nuts and engine cover.
CONNECT VACUUM GAUGE
Using a 3-way connector, connect vacuum gauge to the hose between the actuator and VSV.

Fig 1: Connecting Vacuum Gauge To Hose Between Actuator & VSV

START ENGINE
INSPECT INTAKE AIR CONTROL VALVE
1. While the engine is idling, check that the vacuum gauge needle does not move.
  
  Fig 2: Inspecting Intake Air Control Valve (1 Of 2)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Rapidly depress the accelerator pedal to fully open position and check that the vacuum gauge needle momentarily fluctuates approx. 33.3 kPa (250 mmHg, 9.84 in.Hg) or more. (The actuator rod is pulled down.)
  
  Fig 3: Inspecting Intake Air Control Valve (2 Of 2)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
REMOVE VACUUM GAUGE
Remove the vacuum gauge, and reconnect the vacuum hoses to their proper locations.
REINSTALL ENGINE COVER
Reinstall the engine cover with the 4 nuts.