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单选题
An individual injection pump is designed for variable beginning and constant ending of injectionFor diesel engines operating at constant speeds, the start of injection will（）
A
advance as the load increases
B
retard as the load increase
C
remain unchanged regardless
D
always occur at top dead center
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a variable displacement axial piston pumpB
a constant displacement axial piston pumpC
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单选题A full-flow 50μm filter is installed ,（） so the injection system components on the main engine are safeguarded.A
as close to the main engine as possibleB
as close to the main pump as possibleC
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单选题The effective stroke of a constant-stroke, individual, fuel injection pump is varied by the （）.A
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none of the above
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tiltable discB
gravity discC
distributing discD
catch plate
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单选题Injection lag in a diesel engine may be caused by（）A
a higher cetane number of fuel oilB
the diesel fuel used having a high viscosityC
mechanical rigidity in the lube pump mechanismD
a decrease rigidity in the fuel pump delivery pressure
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单选题（） is not properly set thus causing either advanced or retarded firing.A
A pistonB
A fuel injection pumpC
A feed water pumpD
A lube oil pump
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单选题If fuel injection to a four-stroke/cycle diesel engine begins earlier than designed, ignition may be delayed because the （）.A
cylinder compression pressure may not be high enoughB
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单选题When the tilting box of a variable stroke axial-piston pump is perpendicular to the pump shaft, which of the following conditions will exist?（）A
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单选题The purpose of the delivery check valve used in a diesel fuel injection jerk pump is to （）.A
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allow oil backflow from the injector to the helixC
reduce fuel oil pressure between injection strokesD
meter the quantity of fuel delivered
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improper adjustmentsB
contaminated fuelC
kinked fuel linesD
excessive engine vibration
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slide blockB
tilting boxC
pintleD
reaction ring
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pump plunger diameterC
plunger control rack positionD
total pump stroke
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cylinder
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a gearB
a camC
a rodD
a miler
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单选题The major cause of problems occurring with fuel injection equipment is（）A
incorrect replacement of barrels and plungers of jerk pumpsB
overheating of the nozzle orificesC
cracked pump housingsD
dirt in the fuel
考题
单选题Which of the fuel injection systems listed uses a spring loaded differential spray needle valve and individual pump for each cylinder?（）A
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Air injectionC
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考题
单选题In a common rail engine, the fuel is injected into cylinders（）A
by injection pumpsB
at a time decided by the injection pump timingC
by a signal opening the magnetic valvesD
at a time decided by the cam directly
考题
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