engine racing meaning in English

发电机飞车
发动机超速转
发动机的高速空转
发动机高速空转

The driver waited for the green light , his engine racing .
那司机等候绿灯放行，让发动机空转着。
The motor engine raced before it was shut off
汽车引擎未被关停之前一度加快。
The motor engine raced before it was shut off
汽车发动机关闭之前快速空转。
The driver waited for the green light , his engine racing
那司机等候绿灯放行，让发动机空转著。
Don ' t let the engine race
不要让这发动机空转太快。