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 And VSV
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
START ENGINE
INSPECT INTAKE AIR CONTROL VALVE
1. While the engine is idling, check that the vacuum gauge needle does not move.
  
  Fig 2: Checking Vacuum Gauge Needle Does Not Move (Engine Is Idling)
  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.)
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.