Federal Pickup, Land Cruiser, Starlet & Tercel
- Disconnect vacuum hoses from ports "P", "Q" and "R" of vacuum modulator. Plug port "P" and "R", and blow air into port "Q". Air should escape through air filter of modulator.
- Start engine and raise speed to 2000-2500 RPM. Blow through port "Q" again. There should be resistance to air flow. If not, replace vacuum modulator.