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单选题
Heat damage to fuel injection nozzles on small high-speed diesel engines, can be prevented by（）
A
employing fuel oil as a cooling medium
B
preventing hard carbon deposit on nozzle tips
C
avoiding fuel oil temperature exceeding builder’s specification
D
ensuring good metallic contact between nozzles and cylinder heads
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考题
_______can be a direct cause of faulty operation of diesel engine fuel injection nozzles.A.Excessive fuel nozzle holder coolingB.Sediment in the fuel supplyC.Distortion of the fuel spray patternD.Improper atomization of the fuel
考题
The primary danger in helicopter fires is ______.A.burning jet fuel running on to quarters or other areasB.loss of stabilityC.rotating and flying debrisD.heat damage to helicopter structure
考题
单选题The main purpose of changing main engine to electronic controlled is not to（）A
control fuel injection time more preciselyB
control fuel injection rate more preciselyC
meet the environmental requirementsD
meet high engine speed requirements
考题
单选题Before shutting off the fuel supply to stop a medium or high–speed diesel engine, why is it necessary to allow the engine to idle for a few minutes?（）A
To prevent internal damage form local overheatingB
To ensure the fuel nozzles are flushed cleanC
To clear the smoke stackD
To let the waste heat boiler reduce its rate of steam generation
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The air supplied to a diesel engine is compressed to （） (1) provide heat for the ignition of the fuel (2) decrease injection delayA
(1) only is correctB
(2) only is correctC
both (1) and (2) are correctD
neither (1) or (2) are correct
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 the needle valve in a fuel injection nozzle sticks open （）.A
no fuel will be delivered through the nozzleB
the nozzle will overheat and crackC
time of injection will changeD
fuel will leak into the drain line
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Failure of fuel injection is usually due to trouble in the （）.A
exhaust valvesB
mechanical lubricatorsC
cooling water pumpsD
fuel injection pumps
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Heat damage to fuel injection nozzles can be prevented by avoiding （）A
excessive fuel oil temperatureB
long periods of engine overloadC
metallic contact between nozzles and cylinder headsD
hard carbon deposit and varnish on the nozzles
考题
单选题Most fuel injection nozzles are opened by （）.A
fuel oil pressureB
a cam operated followerC
a spring-loaded pressure plateD
timing gears keyed to the crankshaft
考题
单选题The main source of fuel injection system malfunctions is （）A
improper adjustmentsB
contaminated fuelC
coated fuel linesD
excessive vibration
考题
单选题The term “proper metering”, as applied to a diesel fuel injection system, can be best defined as （）.A
delivering the same quantity of fuel to each cylinder for each power stroke according to engine loadB
maintaining the metering adjustment for a reasonable period under all load conditionsC
timing fuel injection to obtain maximum power and good fuel economyD
distributing the fuel to all parts of the combustion chamber for proper combustion
考题
单选题Which of the following is true about the fuel injection with an ordinary diesel engine?（）A
The process begins after TDCB
The process ends before TDCC
When the piston is near to the TDC the fuel injection endsD
None of the above is true
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Faulty operation of diesel engine fuel injection nozzles can be a direct cause of（）.A
excessive fuel nozzle holder coolingB
sediment in the fuel supplyC
distortion of the fuel spray patternD
improper atomization of the fuel
考题
单选题Fuel is admitted to a diesel engine cylinder through the （）.A
intake valvesB
carburetorC
exhaust portsD
injector nozzles
考题
单选题Faulty operation of diesel engine fuel injection nozzles can be directly caused by （）.A
water in the fuel oil supplyB
excessive fuel nozzle holder coolingC
a distorted fuel spray patternD
leakage past the plunger into the oil drain
考题
单选题Before being shut down, a diesel engine should idle a few minutes in orderto （）A
prevent governor surging at shutdownB
make sure the fuel nozzles are flushed cleanC
prevent pressure buildup in the fuel linesD
prevent damage from localized overheating
考题
单选题To minimize the formation of carbon deposits on fuel injection nozzles, you should （）A
avoid using liquid-cooled nozzles whenever possibleB
avoid low cooling water temperaturesC
avoid prolonged overloading of the engineD
make certain the gasket seal between the nozzle and cylinder head is tight
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Air in the fuel lines to the fuel injection nozzles of a diesel engine will cause the engine to （）A
burn excessive amounts of lube oilB
overheat without smokingC
operate with reduce power or stopD
run away without load
考题
单选题Air in the fuel lines to the fuel injection nozzles of a diesel will result in （）.A
lower compression pressuresB
overheating without smokingC
failure to startD
a run away without load
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