| 摘要 |
PURPOSE:To stabilize an exhaust gas purification performance, by correcting an air-fuel ratio according to an engine temperature with use of a delay period from a timing when an actual A/F ratio is changed from a rich condition to a lean condition and vice versa to a timing when an A/F ratio feedback correction signal is inverted. CONSTITUTION:A delay period A from a timing when an O2 sensor output is transferred from a lean condition through a decision level S to a rich condition to a timing when an A/F ratio feedback correction signal is inverted to start correcting a fuel injection amount to a decreased side is changed according to a fuel temperature. Similarly, a delay period B from a timing when the O2 sensor output is transferred from the rich condition through the decision level S to the lean condition to a timing when the feedback correction signal is inverted to start correcting the fuel injection amount to an increased side is changed according to the fuel temperature. Thus, a suitable A/F ratio feedback correction may be effected according to an engine temperature. As a result, it is possible to prevent an A/F ratio from becoming lean upon hot restarting and stabilize an exhaust gas purification performance. |
