网友您好， 请在下方输入框内输入要搜索的题目：
题目内容
（请给出正确答案）
单选题
In conventional systems, the injection pressure（）, while it’s（）in common rail diesel engines.
A
fluctuates with the engine speed to some extent, independent of the engine speed
B
keeps constant at all engine speed, dependent on the engine speed to some extent
C
keeps constant at all engine speed, independent of the engine speed
D
is decided by the engine speed, constant at all engine speed
参考答案
参考解析
解析：
暂无解析
更多 “单选题In conventional systems, the injection pressure（）, while it’s（）in common rail diesel engines.A fluctuates with the engine speed to some extent, independent of the engine speedB keeps constant at all engine speed, dependent on the engine speed to some extentC keeps constant at all engine speed, independent of the engine speedD is decided by the engine speed, constant at all engine speed” 相关考题
考题
If fuel injection to a four-stroke/cycle diesel engine begins earlier than designed, ignition may be delayed because theA.cylinder compression pressure may not be high enoughB.cylinder compression temperature may be too highC.fuel oil injection pressure may not be high enoughD.scavenge and purge process is incomplete
考题
What kind of pressure systems travel in easterly waves ________．A.High pressureB.Low pressureC.Subsurface pressureD.Terrastatic pressure
考题
单选题When the opening pressure of a diesel fuel injector is greater than that specified by the engine manufacturer，the （）A
quantity of fuel injected is decreasedB
quantity of fuel injected will always be increasedC
start of injection is advancedD
duration of injection will always be greater
考题
单选题Lube oil cannot be efficiently filtered if its （）.A
viscosity is too lowB
temperature is too lowC
pump discharge pressure is higher than the systems pressureD
pump capacity is greater than the systems needs
考题
单选题The primary function of a fuel delivery check valve assembly is to（）A
deliver proper fuel quantity to the injection nozzleB
provide rapid fuel injection cutoffC
control fuel quantity entering the pump bodyD
control fuel pressure delivered to the combustion chamber
考题
单选题If a cam-controlled engine has a normal injection pressure at rated speed,the injection pressure will be（）at slow speed.A
a little lowerB
a little higherC
too lowD
exactly the same
考题
单选题Late fuel injection timing is indicated by （）A
lower than normal cylinder pressure and low exhaust temperatureB
lower than normal cylinder pressure and high exhaust temperatureC
higher than normal cylinder pressure and low exhaust temperatureD
higher than normal cylinder pressure and high exhaust temperature
考题
单选题Which of the following hydraulic systems is not one of the three sub-division of the Hydraulic drive system?（）A
Constant pressure systemB
Variable pressure systemC
Variable displacement systemD
Constant volume system
考题
单选题The replacement piping for diesel engine high pressure fuel systems must be the same length and diameter as the original piping to （）.A
avoid unnecessary pints inventoryB
keep torsional vibration constantC
use existing supports and bracesD
maintain specified injection characteristics
考题
单选题Excessive diesel engine back pressure may be an indication of （）A
carbon buildup in the exhaust manifoldB
overcooling of the exhaust manifoldC
eroded muffler baffle platesD
high injection pressure
考题
单选题When the opening pressure of a diesel engine fuel injector is greater than that specified by the engine manufacturer, which of the following problems can be expected?（）A
Quantity of fuel injected tends to be decreasedB
Quantity of fuel injected will always be increasedC
Start of injection tends to be advancedD
Duration of injection will always greater
考题
单选题If a camshaft-less engine has a normal injection pressure at rated speed, the injection pressure will be at slow speed（）A
too lowB
a little lowerC
a little higherD
exactly the same
考题
单选题In the common rail system, excessive pressure in the header may be caused by （）A
improper adjustment of the bypass valveB
a dribble in the fuel injection nozzleC
insufficient leak-off through injection nozzle packingD
a malfunctioning injection nozzle
考题
单选题During the fuel injection period, fuel pressure must exceed cylinder gas pressure to （）.A
ensure penetration and distribution of the fuel in the combustion chamberB
ensure the needle valve is flushed clean during each injectionC
prevent combustion gas blowback into the open needle valveD
prevent reflected pressure waves when the needle valve closes
考题
单选题The high pressure in fuel injection system of the diesel engine is produced by the （）.A
injector pumpB
fuel injectorC
governorD
turbocharger
考题
单选题The rate of fuel injection in a diesel engine cylinder depends primarily on （）.A
the size of the holes in the fuel nozzleB
timing of the pumpC
supply pressure to the pumpD
shape of the combustion chamber
考题
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
cylinder compression temperature may be too highC
fuel oil injection pressure may not be high enoughD
scavenge and purge process is incomplete
考题
单选题Which of the following problems may occur if the opening pressure of a fuel injection nozzle is greater than specified by the engine manufacturer?（）A
The amount of fuel injected will be increasedB
The start of injection will be retardedC
The nozzle will permit fuel to dribbleD
The spray pattern will be distorted
考题
单选题The purpose of the delivery check valve used in a diesel fuel injection jerk pump is to （）.A
assist in a quick cutoff of fuel injectionB
allow oil backflow from the injector to the helixC
reduce fuel oil pressure between injection strokesD
meter the quantity of fuel delivered
考题
单选题Late fuel injection in a diesel engine is indicated by low firing pressure with （）A
low exhaust temperatureB
low exhaust pressureC
mechanical knock in each cylinderD
black or gray exhaust smoke
考题
单选题An increase in the fuel injection pump discharge pressure can be caused by a/an （）A
leaking delivery valveB
excessive bearing end playC
plugged injector spray holeD
increased plunger stroke
考题
单选题（）uses one or two high pressure pumps for all the cylinders with one more standby, while（）have a separate high-pressure pump for each cylinder.A
A common rail engine；conventional enginesB
A conventional engine；common rail enginesC
A marine diesel engine；most other enginesD
A two-stroke engine；four-stroke engines
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
Common-rail injectionB
Air injectionC
Jerk pump injectionD
Distribution injection
考题
单选题Fuel injection systems meter fuel, atomize fuel, and （）.A
create turbulence in the combustion chamberB
aid in completing cylinder scavengingC
inject fuel at the proper timeD
minimize fuel penetration into the cylinder
考题
单选题The minimum fuel oil delivery pressure required for diesel engine injection depends primarily on the（）A
degree of cylinder air turbulenceB
firing pressure in the engineC
quality of fuel to be injectedD
duration of the ignition delay period
考题
单选题What kind of pressure systems travel in easterly waves（）.A
High pressureB
Low pressureC
Subsurface pressureD
Terrastatic pressure
热门标签
最新试卷
