| 摘要 |
PURPOSE:To reduce the quantity of HC discharged, by obtaining adequate ignition timing by detecting the negative pressure of an auxiliary mixture passage and by working the negative pressure to a negative pressure system ignition timing controller when a coasting richer is operated. CONSTITUTION:A main advance port 4 and an auxiliary advance port 36 sense atmospheric pressure under a condition that an engine is non-load operated. A vacuum advancer 23 of a distributor 22 does not function, and the action of the angle of the lead of ignition timing is stopped. When the engine enters a deceleration operation condition and deceleration is sudden, an opening and shutting valve 12 of a coasting richer is opened by the function of a diaphragm 14. The auxiliary advance port 36 senses negative pressure from a coasting nozzle 9, and sends a negative pressure signal to a control valve 32 through a duct 35. Negative pressure sensed by means of the auxiliary advance port 36 is conducted to a diaphragm chamber 25 of the distributor 22, and the action of the angle of the lead of ignition timing is performed. |
