The （） in the injector will lift at a pre-set pressure which ensures that the fuel will atomize once it enters the cylinder.

The plunger in the fuel injector pump， usually operated by a （）， is driven up and down when working.

As the plunger moves up， the ports are closed and the fuel （） and delivered to the injector nozzle at very high pressure.

The needle valve in the injector （） at a pre-set pressure which ensures that the fuel will atomize once it enters the cylinder.

Combustion knock occurring in a diesel engine can be caused by _____. A.low coolant temperature B.insufficient fuel C.high ambient temperature D.carbon buildup on the injector tips