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The amount of fuel injected in a particular time, or degree, of crankshaft rotation is termed ().
A . metering
B . timing
C . rate of injection
D . rate of distributio
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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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The fuel injection pumps on a diesel engine are controlled by a linkage system attached to the ()
A . camshaft
B . crankshaft
C . governor
D . flywheel
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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 load
B . maintaining the metering adjustment for a reasonable period under all load conditions
C . timing fuel injection to obtain maximum power and good fuel economy
D . distributing the fuel to all parts of the combustion chamber for proper combustio
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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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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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Movement of the pump control rack in a fuel injection system using individual plunger-type pumps ()
A . changes the position of the fuel inlet ports
B . changes the length of the pump stroke
C . varies the quantity of fuel delivered
D . varies the compression of the delivery valve spring
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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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Faulty operation of diesel engine fuel injection nozzles can be a direct cause of().
A . excessive fuel nozzle holder cooling
B . sediment in the fuel supply
C . distortion of the fuel spray pattern
D . improper atomization of the fuel
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Fuels of different qualities may require advancing or retarding the injection timing, in addition to which if the injection timing is advanced when the engine is running at loads below the (), then a saving in fuel can be achieved.
A . BHP
B . MCR
C . IHP
D . MEP
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Fuel has to be injected into the engine at a high pressure so that it () correctly.
A . is purified
B . in timed
C . is compressed
D . atomize
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When ship is fouled, increasing the fuel injection for keeping the normal speed will cause the main engine ()
A . to work as overload characteristic
B . overspeed
C . over mechanical load only
D . over thermal load only
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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 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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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 injector
B . fuel will not be properly atomized in the cylinder
C . maximum expansion of the burned fuel cannot take place in the cylinder
D . compression pressure will be too low to cause fuel ignitio
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Modern marine diesel engines using mechanical fuel injection, operate on a combustion cycle which is()
A . a combination of constant volume and constant pressure
B . a combination of constant temperature and constant pressure
C . entirely constant pressure
D . entirely constant volume
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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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Generally speaking,the fuel injected into a marine diesel engine combustion chamber is ignited by().
A . spark plugs
B . glow plugs
C . heat of compression
D . a magneto
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The amount of fuel injection into a diesel engine cylinder by a unit injector, is controlled by()
A . the firing pressure in the cylinder
B . a metering helix inside the pump
C . varying the physical length of the plunger stroke
D . varying the clearance between the injector cam and the injector rocker arm
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Late fuel injection in a diesel engine is indicated by low firing pressure with()
A . high exhaust temperature
B . low exhaust temperature
C . fuel knock in each cylinder
D . mechanical knock in each cylinder