Throttle Opener: Tacoma

Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article.
With engine idling, disconnect and plug vacuum hose at throttle opener. See Fig 1. Note engine speed with vacuum hose disconnected from throttle opener. Engine speed should be 1200-1500 RPM.
Throttle opener is nonadjustable. If engine speed is not within specification, replace throttle body. Shut engine off. Reinstall vacuum hose on throttle opener. Start engine and ensure engine returns to proper idle speed.

Fig 1: Locating Throttle Opener & Disconnecting Vacuum Hose (Tacoma)