| 摘要 |
PROBLEM TO BE SOLVED: To reduce NOx emitted from an engine as well as prevent its misfire especially under low load when an ignition point is set near the range causing misfire. SOLUTION: Calculating means 41 and 42 calculate an air-fuel ratio and ignition timing in lean-burn drive respectively, and a detecting means 43 detects the roughness of an engine. If the roughness is in a level below an allowance value, a correcting means 44 corrects the air-fuel ratio in lean-burn drive larger and retards the ignition timing in lean-burn drive to bring the roughness up to the maximum level in its stability. |
