单项选择题
A.low exhaust back pressure
B.early fuel injection in one of the cylinders
C.compression pressure in one of the cylinders
D.plugged injector holes
单项选择题 A diesel engine emits blue exhaust smoke as a result of（）
单项选择题 Because of the close tolerances used in diesel engine fuel oil pumps, a worn plunger requires（）
单项选择题 Which of the following statements represents the function of the compression rings installed at the top of a diesel Engine piston?（）