单项选择题
A.hold the valves open B.keep the valves off their seats until the exhaust stroke is completed C.close the valves D.open inlet valves when the air injection cycle begins
Worn diesel engine intake valve guides can result in （）...
单项选择题Worn diesel engine intake valve guides can result in （）
A.increased engine breathing efficiency B.excessive valve lash C.excessive lube oil consumption D.lower than normal fuel consumption
If a diesel engine runs roughly, which of the systems l...
单项选择题If a diesel engine runs roughly, which of the systems listed is most likely to be at fault?（）
A.Fuel B.Lubricating C.Cooling D.Ignition
Excessive piston ring wear in a diesel engine will caus...
单项选择题Excessive piston ring wear in a diesel engine will cause（）
A.high lube oil viscosity B.increased lube oil consumption C.low lube oil temperatures D.high firing pressures
