更多"When a diesel engine compression pr"的相关试题:
[单项选择]Low compression pressure in a diesel engine may be the result of （）
A. insufficient fuel supply due to fuel pump valves sticking or leaking
B. excessive mechanical clearance between the piston crown and cylinder head
C. excessively worn fuel pump plunger
D. excessive exhaust back pressure
[单项选择]Low compression pressure in a diesel engine is caused by（）
A. low water in the expansion tank
B. improperly seated valves
C. low fuel oil pressure
D. worn or broken cylinder liner sealing rings
[单项选择]Low compression pressure in a diesel engine can be caused by（）
A. improperly seating intake valves
B. leaking cylinder liner seal rings
C. late fuel injection timing
D. carbon deposits on the piston
[单项选择]
In a diesel engine, when installing new piston rings it is important to check（）
Ⅰ.ring gap clearance
Ⅱ.side clearance
A. Ⅰ only
B. Ⅱ only
C. both Ⅰ and Ⅱ
D. neither Ⅰnor Ⅱ
[单项选择]
In a diesel engine, when refitting piston rings you should （）
Ⅰ.check the ring gap at the smallest diameter of the cylinder
Ⅱ. Remove carbon from the ring groove
A. Ⅰ only
B. Ⅱ only
C. both Ⅰ and Ⅱ
D. neither Ⅰ nor Ⅱ
[单项选择]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
[单项选择]On a four-stroke diesel engine, when the piston is driven downwards by the expanding gas, it delivers power to the crankshaft through the （）.
A. thrust block
B. sounding rod
C. connecting rod
D. push rod
[单项选择]For a diesel engine, when the piston is at the （）, the clearance volume is the largest.
A. TDC
B. DTC
C. BDC
D. DBC
[单项选择]A supercharged diesel engine when compared to a similar naturally aspirated diesel engine, will develop an increase in （）
A. ignition lag
B. engine horsepower
C. lube oil system pressure
D. specific fuel consumption
[单项选择]An over-speed trip stops a diesel engine when the engine （）
A. runs out of fuel
B. has low lubricating oil pressure
C. exceeds a set maximum speed
D. has high cooling water temperature
[单项选择]If a diesel engine rotates slowly when cranked, but does not fire, the（）
A. fuel control rack had admitted excessive fuel
B. engine speed does not match the fuel rack setting
C. engine has failed to reach its firing speed
D. starter pinion and ring gear contact is not correct
[单项选择]When one cylinder has a lower compression pressure and higher exhaust gas temperature than any of the other engine cylinders, which of the conditions listed will indicated?（）
A. Advanced ignition
B. Clogged air intake
C. Leaky exhaust valve
D. High exhaust pressure
[单项选择]Diesel engine air start system check valves are opened by （）
A. an air start cam
B. cylinder compression pressure
C. starting air pressure
D. valve springs
[单项选择]When monitoring diesel engine performance, the most useful instrument to use is the （）
A. dwell-tachometer
B. exhaust gas pyrometer
C. fuel flow rate mete
D. exhaust gas analyzer
[单项选择]When restarting a heavy fuel diesel engine that has been stopped for some time, the engine should（）
A. increase the starting air pressure
B. use a higher than normal cranking speed
C. increase the fuel injection pressure
D. use a fuel having a lower ignition temperature
[单项选择]When the opening pressure of a diesel engine fuel injector is greater than that specified by the engine manufacturer, which of the following problems can be expected?（）
A. Quantity of fuel injected tends to be decreased
B. Quantity of fuel injected will always be increased
C. Start of injection tends to be advanced
D. Duration of injection will always greater
[单项选择]When fuel is injected in a diesel engine cylinder too early, （）
A. ignition may be delayed
B. fuel economy is not affected
C. exhaust gas temperature will be unchanged
D. the exhaust will be clear
[单项选择]The knock occurring when a cold diesel engine is started and continues while running at low speed, but stops when the engine reaches normal operating speed and temperature, is（）.
A. caused by retarded injection timing
B. caused by a mechanical defect in one cylinder
C. caused by high fuel injection pressures
D. normal for these conditions
