更多"The amount of fuel injected in a pa"的相关试题:
[单项选择]The amount of fuel injection into a diesel engine cylinder by a unit injector, is controlled by（）
A. the firing pressure in the cylinder
B. a metering helix inside the pump
C. varying the physical length of the plunger stroke
D. varying the clearance between the injector cam and the injector rocker arm
[单项选择]The amount of fuel delivered by a helical plunger fuel injection pump is controlled by （）
A. varying the pump discharge pressure
B. varying the pump return pressure
C. rotation of the pump plunger
D. rotation of the pump barrel
[单项选择]The amount of fuel delivered by a unit injector is controlled by the （）
A. camshaft
B. main spring
C. rack position
D. nozzle orifice size
[单项选择]It should be evident that the amount of fuel injected into the cylinder is dependent on the position of the helix relative to the （）.
A. inlet port
B. exhaust port
C. spill port
D. scavenge port
[单项选择]The amount of fuel delivered for each cycle must be in accordance with the engine load, and the same quantity of fuel must be delivered to each cylinder for each power stroke at that load.Which of the following statements describes this requirement?（）
A. Proper timing
B. Accurate metering
C. Suitable injection rate
D. Suitable atomization rate
[单项选择]In a unit injector the amount of fuel that will be forced through the spray nozzle on each stroke of the plunger depends on （）
A. the pump supply pressure
B. the slope of the fuel cam
C. how the plunger is rotated
D. the number of sleeve segments engaged with the rack
[单项选择]Fuel droplets injected into a diesel engine cylinder must have adequate penetration to （）
A. prolong the ignition delay period
B. ensure the beginning of fuel injection
C. thoroughly utilize the air charge
D. allow controlled fuel combustion
[单项选择]Fuel injected into a diesel engines cylinder is ignited by （）.
A. the heat compressed fuel/air mixture in the cylinder
B. the fuel igniter
C. the fuel injector
D. the fuel pump
[单项选择]Generally speaking，the fuel injected into a marine diesel engine combustion chamber is ignited by（）.
A. spark plugs
B. glow plugs
C. heat of compression
D. a magneto
[单项选择]In a jerk pump, the amount of fuel that will be forced through the spray nozzle on each upward stroke of the plunger depends on （）
A. the pump supply pressure
B. the slope of the fuel cam
C. how the plunger is rotated
D. the number of sleeve segments engaged with the rack
[单项选择]When fuel is injected in a diesel engine cylinder too early, （）
A. ignition may be delayed
B. fuel economy is not affected
C. exhaust gas temperature will be unchanged
D. the exhaust will be clear
[单项选择]Fuel has been injected but ignition fails The possible cause may be （）.
A. leaky exhaust valve
B. increased scavenging air temperature
C. engine cylinders not scavenged sufficiently
D. water in the fuel oil
[单项选择]Fuel oil injected into the cylinder of a diesel engine just after the piston passes top dead center, will（）
A. increase engine power
B. increase engine load
C. decrease engine power
D. improve fuel economy
[单项选择]When fuel is injected late into a diesel engine cylinder,（）.
A. the exhaust will be clear
B. fuel consumption will be low
C. all the fuel will be burned at top dead center
D. fuel consumption will be high
[单项选择]In a common rail engine, the fuel is injected into cylinders（）
A. by injection pumps
B. at a time decided by the injection pump timing
C. by a signal opening the magnetic valves
D. at a time decided by the cam directly
[单项选择]In a diesel engine, when the fuel is injected into the cylinder,（）
A. the piston is just coming upward from the bottom dead center
B. the piston has moved about one-fifth of the way up
C. the piston has moved most of the way up and almost reached the TDC
D. the piston has just past the TDC
[单项选择]Fuel has to be injected into the engine at a high pressure so that it （） correctly.
A. is purified
B. in timed
C. is compressed
D. atomizes
[单项选择]The amount of expansion space to be left in a fuel tank when fuel oil is being received, is determined by the （）.
A. quantity of fuel to be received
B. flash point of the fuel as it is received
C. fuel temperature as it is received
D. viscosity of the fuel being received
[单项选择]Fuel injection systems meter fuel, atomize fuel, and （）.
A. create turbulence in the combustion chamber
B. aid in completing cylinder scavenging
C. inject fuel at the proper time
D. minimize fuel penetration into the cylinder
