TOYOTA Air Injection: Operation: Notes

Air under pressure from air pump flows through a check valve to air distribution manifold where it enters the exhaust manifold through air injection nozzles. A check valve is used to prevent a back flow of exhaust gas from entering air pump when exhaust pressure exceeds air pump delivery pressure. During periods of engine deceleration, air is diverted to atmosphere through by-pass valve to prevent engine popping. Operation of individual components is as follows: