Removal (LS400)
- Intake Air Control (IAC) valve is bolted to underside of upper intake manifold. Remove engine cover. Remove battery cover, air cleaner inlet and intake air connector. Release fuel pressure. See FUEL SYSTEM PRESSURE RELEASE under FUEL SYSTEM.
- Disconnect fuel inlet hose. Remove throttle body from intake manifolds. See THROTTLE BODY under FUEL SYSTEM. Disconnect accelerator cable. Disconnect throttle position sensor connector. See Figure. Disconnect accelerator pedal position sensor and throttle motor connectors.
- Disconnect EVAP and ACIS vacuum switching valve connectors. Disconnect fuel injector connectors. Disconnect noise filter connector. Disconnect brake booster vacuum hose from union on intake manifold. Disconnect PCV hose from PCV valve. Disconnect EVAP hose from EVAP pipe. Disconnect EVAP vacuum switching valve hose. Disconnect power steering air hose from intake manifold.
- Remove EVAP pipe from intake manifold. Remove accelerator cable bracket. Remove engine cover brackets. Remove EVAP vacuum switching valve. Disconnect wiring harness clamps from wire clamp bracket on right fuel rail.
- Remove bolts and disconnect engine wiring harness protector from rear water by-pass joint and right cylinder head. Remove bolts and disconnect engine wiring harness protector and wire clamp bracket from intake manifold. Remove upper and lower intake manifolds as an assembly.
- Disconnect vacuum hose from ACIS actuator. Remove bolts, and disconnect ACIS vacuum switching valve connector from upper intake manifold. Remove nuts, bolts, accelerator cable bracket and engine cover bracket. Separate upper and lower intake manifold, and remove gasket. Remove IAC valve from upper intake manifold. See Figure.