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If the diesel engine fuel injection timing is changed to delay the start of injection until the pistons are at top dead center, the engine will()
A . backfire through the air intakes
B . develop less power under load
C . have high firing pressures
D . lift its cylinder relief valve
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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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The effective pump stroke of an individual port-and-helix fuel injection pump is determined by the ()
A . fuel delivery pressure
B . pump plunger diameter
C . plunger control rack position
D . total pump stroke
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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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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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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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The injection may be delayed, ()the pumps are in good order, if the fuel lines to the injection valves have not been cleared of air.
A . because
B . though
C . since
D . until
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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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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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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 increased
B . The start of injection will be retarded
C . The nozzle will permit fuel to dribble
D . The spray pattern will be distorted
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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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The operation between two fuel injections is called a working cycle, which consists of a fixed sequence of eventsWhat does "which" mean in this sentence?()
A . a working cycle
B . the operation
C . two fuel injections
D . event
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With VIT unit the timing of fuel injection of an engine can be regulated automatically according to the ().
A . ship draft
B . pitch
C . engine load
D . oil viscosity
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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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It should be evident that the amount of fuel injected into the cylinder is dependent on the position of the helix relative to the ().
A . inlet port
B . exhaust port
C . spill port
D . scavenge port
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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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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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A practical way of checking for excessive fuel injection in one cylinder of an operating diesel engine is to ()
A . feel the high pressure fuel line
B . check the cylinder exhausts for white smoke frequently
C . check the cylinder exhaust temperature
D . isolate each cylinder and inspect the injector
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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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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 injection
B . allow oil backflow from the injector to the helix
C . reduce fuel oil pressure between injection strokes
D . meter the quantity of fuel delivered
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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