Warm engine to normal operating temperature. Ensure idle speed is correct. See IDLE SPEED & MIXTURE in ADJUSTMENTS - 2.4L article. Remove cap, filter and separator from dashpot. See Fig 1.
Start engine. Maintain engine speed at specified testing RPM. See DASHPOT TESTING SPECIFICATIONS table. Plug Vacuum Transmitting Valve (VTV) hole with your finger. See Fig 2.
Release throttle. Dashpot should be extended and dashpot setting RPM should be as specified. See DASHPOT TESTING SPECIFICATIONS table. If dashpot setting RPM is incorrect, rotate dashpot adjusting screw to obtain correct RPM. See Fig 3.
Repeat step 3) and ensure proper adjustment is obtained. To check Vacuum Transmitting Valve (VTV) operation, operate engine at dashpot testing RPM for a few seconds. Release throttle. Ensure engine returns to idle in approximately one second.
Install separator, filter and cap. Ensure filter is installed with the coarse surface facing outward (away from dashpot).

DASHPOT TESTING SPECIFICATIONS

Application	Testing RPM	Dashpot Setting RPM
M/T	2500	2000

Fig 1: Identifying Dashpot & Components

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Dashpot Control System: M/T