Throttle Opener: Es300
Start engine and warm engine to normal operating temperature. Ensure idle speed is 650-750 RPM. Disconnect and plug vacuum hose at throttle opener near throttle body. See Fig 1. Note engine speed. Engine speed should be 1100-1700 RPM. If engine speed is not 1100-1700 RPM, replace throttle body. See THROTTLE BODY under FUEL SYSTEM in REMOVAL & INSTALLATION - EXCEPT GX470 article.