摘要 |
Passage means communicating an EGR passage between first and second EGR control valves with a vacuum chamber of an actuator of the second EGR control valve is prevented from being clogged by solids of the engine exhaust gases by the provision of an air pump for feeding air to fill the passage means between an orifice therein and the EGR passage with air and to make the amount of engine exhaust gases passing through the orifice nearly zero. |