-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
Indirect cooling of fuel injector nozzle holders for diesel engines is accomplished primarily by （）.
A . heat conduction into the injected fuel oil
B . heat conduction into the water jacket wall
C . water circulation through passages in the holder
D . fuel oil circulation through passages in the holder
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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 head
-
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
-
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
-
Early fuel injection timing is indicated by the cylinder pressure being（）
A . above normal with a below normal exhaust temperature
B . above normal with a normal exhaust temperature
C . below normal with a normal exhaust temperature
D . below normal with an above normal exhaust temperature
-
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
