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Failure of fuel injection is usually due to trouble in the ().
A . exhaust valves
B . mechanical lubricators
C . cooling water pumps
D . fuel injection pum
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Fuel injection valves should be taken out, cleaned, and lifting checked every ().
A . two to four months
B . four to six months
C . six to eight month
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Problems with the diesel engine fuel injection pump are usually caused by()
A . improper adjustment
B . contaminated fuel
C . kinked fuel lines
D . excessive engine vibratio
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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 combustio
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Heat damage to fuel injection nozzles can be prevented by avoiding ()
A . excessive fuel oil temperature
B . long periods of engine overload
C . metallic contact between nozzles and cylinder heads
D . hard carbon deposit and varnish on the nozzle
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During the fuel injection period, fuel pressure must exceed cylinder gas pressure to ().
A . ensure penetration and distribution of the fuel in the combustion chamber
B . ensure the needle valve is flushed clean during each injection
C . prevent combustion gas blowback into the open needle valve
D . prevent reflected pressure waves when the needle valve close
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A diesel engine will lose power if fuel injection occurs too early because the ()
A . fuel will not be properly atomized in the cylinder
B . ignition will be delayed due to low ignition temperature
C . maximum fuel expansion will occur on the compression stroke
D . fuel will ignite before top dead center
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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
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Significant retardation of a diesel engine fuel injection timing will result in ()
A . smoother engine operation
B . advanced fuel ignition
C . increased fuel economy
D . reduced engine power
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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
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Dirt lodged on the nozzle valve seat of a fuel injection nozzle will cause()
A . erosion and cratering of the nozzle orifices
B . fuel leakage into the nozzle drain line
C . fuel leakage before and after injection
D . insufficient fuel delivery though that nozzle
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When a fuel injection nozzle overheats, which of the problems listed can be expected?()
A . The fuel metering will vary
B . The fuel will explode
C . The cylinder head will crack
D . The engine will sto
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If the needle valve in a fuel injection nozzle sticks open ().
A . no fuel will be delivered through the nozzle
B . the nozzle will overheat and crack
C . time of injection will change
D . fuel will leak into the drain line
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Late fuel injection timing is indicated by ()
A . lower than normal cylinder pressure and low exhaust temperature
B . lower than normal cylinder pressure and high exhaust temperature
C . higher than normal cylinder pressure and low exhaust temperature
D . higher than normal cylinder pressure and high exhaust temperature
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Faulty operation of diesel engine fuel injection nozzles can be directly caused by ().
A . water in the fuel oil supply
B . excessive fuel nozzle holder cooling
C . a distorted fuel spray pattern
D . leakage past the plunger into the oil drai
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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
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The sequence of fuel injection into cylinders is determined by ().
A . the steering
B . the driven gear
C . the turning gear
D . the timing gear
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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
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Air in the fuel lines to the fuel injection nozzles of a diesel will result in ().
A . lower compression pressures
B . overheating without smoking
C . failure to start
D . a run away without load
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The major cause of fuel pump and injection system problems is ()
A . improper adjustments
B . contaminated fuel
C . kinked fuel lines
D . excessive engine vibratio
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The fuel injector injects a fine spray of fuel into the hot air and combustion (), producing much high pressure in the gases.
A . has begun
B . takes place
C . occurs
D . happe
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Most fuel injection nozzles are opened by ().
A . fuel oil pressure
B . a cam operated follower
C . a spring-loaded pressure plate
D . timing gears keyed to the crankshaft
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If the plunger or barrel of a fuel injection jerk pump becomes damaged,()
A . only the replacement of the entire pump would be acceptable
B . the injection pump and injection nozzle must be replaced
C . either the barrel or plunger must be replaced
D . the barrel and plunger must be replaced as a unit
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To minimize the formation of carbon deposits on fuel injection nozzles, you should ()
A . avoid using liquid-cooled nozzles whenever possible
B . avoid low cooling water temperatures
C . avoid prolonged overloading of the engine
D . make certain the gasket seal between the nozzle and cylinder head is tight