Fuel Ratio Control
电子控制模块（ECM）可自动控制发动机的空燃比，提供最佳的发动机性能，控制排烟和节省燃油。 燃油输送量是根据进气歧管压力（增压压力）来调节的。 随着增压压力升高，气缸内可供燃烧的空气增多。 ECM 则会相应地输送更多的燃油，以便保持最佳的空燃比。
发动机的电子控制系统会根据海拔高度进行补偿。 ECM 通过系统的大气压力传感器来感应大气压。 该传感器可指示机器所处的海拔高度。 ECM 会相应地调整发动机的空燃比。
调整 ECM 中的空燃比控制是通过使用卡特彼勒电子技师（ET）来完成的。 可通过更改"空燃比控制偏移量"参数来补偿冬季混合燃油、用户个人喜好等指标。
将"空燃比控制偏移量"设为正值时会提高空燃比。 该设置会使发动机对机器加速的响应更快，但可能也会增加黑烟排放量。
将"空燃比控制偏移量"设为负值会降低空燃比，从而在一定程度上降低发动机的响应速度，同时减少黑烟排放量。
"空燃比控制偏移量"的绝对值为 25。 这是一个无量纲的数值。 "空燃比控制偏移量"的正常设定值为 0。
注: 改变"空燃比控制偏移量"参数不会影响发动机的总输出功率。
Show/hide table
| "空燃比控制偏移量"的值对黑烟排放和发动机响应速度的影响 | ||
| 值 | 发动机响应 | 黑烟排放 |
| -25 | 较慢 | 黑烟较少 |
| 0 | 一般 | 清洁 |
| 25 | 较快 | 黑烟较多 |
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