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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 enough
B
cylinder compression temperature may be too high
C
fuel oil injection pressure may not be high enough
D
scavenge and purge process is incomplete
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更多 “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” 相关考题
考题
If you suspect a diesel engine is misfiring due to air leakage into the fuel system, you should begin looking for the leak at theA.fuel line connections to the cylinder injection valvesB.gasket surfaces of the fuel oil filtersC.discharge fittings of the fuel injector pumpsD.suction side of the fuel oil transfer pump
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
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In a four-stroke/cycle diesel engine, after the completion of the power stroke, the piston will move()A
up and draw in a fresh air chargeB
down to burn off fuelC
down to compress the fuel air chargeD
up and force out the exhaust gases
考题
单选题The burning of fuel oil in a diesel engine having a high sodium content, will cause ()A
corrosion and grooving of exhaust valvesB
corrosion and gumming of the fuel injection pumpC
salt deposits in the exhaust manifoldD
slag deposits in the fuel injection equipment
考题
单选题Problems with the diesel engine fuel injection pump are usually caused by()A
improper adjustmentB
contaminated fuelC
kinked fuel linesD
excessive engine vibration
考题
单选题Air motion is induced in a four-stroke/cycle diesel engine cylinder to improve air fuel mixing, and is known as()A
superchargingB
scavengingC
turbulenceD
swept volume charging
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The size of the exhaust valve opening is ()A
most critical in a four-stroke cycle diesel engineB
most critical in a two-stroke/cycle diesel engineC
most critical in a four-stroke/cycle diesel engine if it is turbochargedD
of equal importance in a two-stroke/cycle diesel engine as in a four-stroke/cycle diesel engine
考题
单选题Proper lubrication of the main bearings is more easily obtained in a single acting, four-stroke/cycle diesel engine than in a tow-stroke/cycle diesel engine because().A
The direction of pressure on the journal in four-stroke engine is continuouslyB
positive feed lubricators are installed on all bearings of four-stroke engine, whereas as a splash feed system is used on tow-stroke engineC
four-stroke engines usually utilize a heavier grade of oil than tow-stroke enginesD
Low-stroke engines usually consume less lube oil than four-stroke engines
考题
单选题Turbulence is created in the cylinders of a diesel engine to ()A
obtain injection lagB
help mix fuel and airC
increase combustion pressureD
utilize higher injection pressures
考题
单选题High exhaust temperatures from all of cylinder of a turbocharged, four-stroke/cycle diesel engine can be caused by an()A
inoperative turbochargerB
inadequate fuel supplyC
overload on one cylinderD
unequal load distribution
考题
单选题Proper lubrication of the main bearing is more easily obtained in a single acting four-stroke/cycle diesel engine than in a single acting two-stroke/cycle diesel engine because ()A
bearing pressure in a four-stroke/cycle acting single diesel engine is continually reversedB
bearing pressure in a two-stroke/cycle single acting diesel engine is continually reversedC
the maximum bearing pressure is higher in a single acting two-stroke/cycle diesel engineD
two-stoke/cycle diesel engines require more complicated lubrication piping
考题
单选题Scavenging in a four-stroke/cycle diesel engine occurs during the ().A
last part of the exhaust stroke, and the first part of the intake strokeB
last part of the intake stroke onlyC
early part of the injection stroke onlyD
early part of the power stroke
考题
单选题A disadvantage of a four-stroke/cycle diesel engine is ()A
higher working temperature of piston and cylinderB
the use of scavenge portsC
fewer power strokes per revolution of the crankshaftD
part of the fuel is burned as the piston is moving away from top dead center
考题
单选题The fuel injection pumps on a diesel engine are controlled by a linkage system attached to the ()A
camshaftB
crankshaftC
governorD
flywheel
考题
单选题A large two-stroke/cycle direct reversing diesel engine is to be reversedPrior to the admission of starting air you must ()A
line up the engine fore restarting with light diesel oilB
reposition the fuel injection camC
change the intake and exhaust valve cam positionsD
place the starting cam in the intermediate position
考题
单选题Which of the following statements is true regarding the installation of piston rings on two-stroke/cycle, diesel engines as compared to four-stroke/cycle, diesel engines?()A
In a two-stroke/cycle engine, the rings run hotter, requiring the end gap to be greaterB
Some provision must be made in a two-stroke/cycle engine to keep the rings from binding in the portsC
No gap is required to exist between the ends of the ring when cold in a two-stroke/cycle engine, but a small gap is required in a four-stoke/cycle engineD
The gaps should be staggered on either side of a piston in a two-stroke/cycle engine, while staggering is not necessary in a four-stroke/cycle engine
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A two-stroke/cycle diesel engine requires less starting air than a four-stroke/cycle diesel engine, of equal displacement, because the two-stroke/cycle diesel engine()A
has little or no internal frictionB
has a lower effective compression ratioC
operates with scavenge air under a positive pressureD
operates without energy absorbing intake and exhaust strokes
考题
单选题The speed of the turbocharger for a four-stroke/cycle diesel engine driving a generator at constant speed depends on the ()A
engine speedB
kilowatt loadC
fuel injection pressureD
air intake manifold temperature
考题
单选题Significant retardation of a diesel engine fuel injection timing will result in ()A
smoother engine operationB
advanced fuel ignitionC
increased fuel economyD
reduced engine power
考题
单选题A diesel engine will lose power if fuel injection occurs too late in the cycle, because the()A
fuel droplets will burn as they leave the fuel injectorB
fuel will not be properly atomized in the cylinderC
maximum expansion of the burned fuel cannot take place in the cylinderD
compression pressure will be too low to cause fuel ignition
考题
单选题If you suspect a diesel engine is misfiring due to air leakage into the fuel system, you should begin looking for the leak at the ()A
fuel line connections to cylinder injection valvesB
gasket surfaces of the fuel oil filtersC
discharge fitting of the fuel injector pumpsD
suction side of the fuel oil tran
考题
单选题Fuel oil begins injection into the cylinder of a four-stroke/cycle diesel engine during the ().A
intake strokeB
exhaust strokeC
power strokeD
compression stroke
考题
单选题A turbocharged, four-stroke/cycle diesel engine has a larger valve overlap than a naturally aspirated four-stroke/cycle diesel engine, in order to in crease the ().A
temperature of the exhaust gasesB
energy supplied to the turbochargerC
air pressure to the intake manifoldD
purge of exhausted gases from the cylinders
考题
单选题A four-stroke/cycle, 1000horsepower diesel engine fails to start at normal cranking speed with normal fuel pressure and ambient temperatureThe reason for the failure could be()A
glazed liners or pistonsB
high lube oil pressureC
excessive compression ratioD
worn valve seats and valves
考题
单选题When ship navigating in rough sea, the correct operation is ()A
navigating with a low diesel engine speedB
navigating with a stable diesel engine speedC
increasing the efficiency of propellerD
increasing fuel injection
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