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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 vapors given off by heated fuel oil are flammable, explosive, and （）
A . lighter than air
B . heavier than air
C . odorless
D . nontoxic
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The cetane rating of diesel fuel is an indication of the（）
A . ignition quality of the fuel
B . calorific value of the fuel
C . flash point of the fuel
D . rate of fuel consumptio
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Diesel fuel vapors （）.
A . can not be ignited by a spark unless the vapor is in a confined space
B . are nontoxic in all concentrations
C . can not be ignited by a spark unless they are at their auto-ignition temperature
D . are heavier than air
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The ignition quality of diesel fuel is indicated by its（）
A . octane number
B . cetane number
C . viscosity in Saybolt seconds
D . air fuel ratio
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The most common diesel engine fuel system problems are caused by （）.
A . incorrect adjustments
B . dirty fuel
C . broken fuel lines
D . excessive vibratio
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In a diesel engine, the time taken to heat the fuel particles, turn them into vapor, and bring about combustion is called （）
A . injection lag
B . ignition delay
C . compression
D . turbulence lag
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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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What causes diesel fuel to be ignited in the cylinder of an operating diesel engine?（）
A . Spark plug
B . Heat of compression
C . Carburetor
D . Glow ping
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The ignition quality of a diesel fuel is indicated by the （）
A . cetane number
B . volatility point
C . viscosity index
D . octane number
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Which of the following statements is least likely to cause the ignition of fuel vapors?（）
A . Static electricity
B . An open running electric motor
C . Loose wiring
D . Explosion proof light
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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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The vapors given off by heated fuel oil are heavier than air and are（）.
A . odorless
B . explosive
C . nontoxic
D . visible
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When fuel enters the crankcase of a diesel engine, it （）
A . dilutes the lube oil and reduces its viscosity
B . forms sulfuric acid in the lube oil
C . causes pitting and failure of the bearings
D . causes sludge deposits on valve stem
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A diesel engine is warmed up and white vapor is in the exhaust，this could indicate （）
A . excessive cylinder lubrication
B . a lugging engine
C . a leaking cylinder liner
D . overloading of one cylinder
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Fuel is admitted to a diesel engine cylinder through the （）.
A . intake valves
B . carburetor
C . exhaust ports
D . injector nozzle
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Diesel fuel is relatively safe to handle due to its low volatility, but the fumes will self-ignite and continue to burn steadily if the fuel is heated to the （）.
A . flash point
B . auto-ignition point
C . volatility point
D . upper explosive limit
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The cetane number of a diesel fuel oil indicates its（）
A . Viscosity
B . acid content
C . heating value
D . ignition quality
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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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Fuel oil discharged to the diesel engine cylinder is atomized at the （）
A . turbocharger
B . injection nozzle tip
C . carburetor
D . fuel oil pum
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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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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 valves
B . gasket surfaces of the fuel oil filters
C . discharge fitting of the fuel injector pumps
D . suction side of the fuel oil tra
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If it becomes necessary to cutout an individual cylinder of a large, low-speed, main propulsion diesel engine, the fuel to that cylinder should be secured and its （）
A . fuel pump should be removed and all connections blanked off
B . cylinder oil feed rate should be increased slightly above that used at normal sea speed
C . cylinder oil feed rate should be reduced
D . cylinder oil feed rate should be increased to the maximum flow capable of the metering pum
