單項(xiàng)選擇題If a diesel engines exhaust temperature is abnormally high, the cause could be（）

A.too light of a load
B.injection timing is too early
C.overloading of the engine
D.too low of a compression ratio


您可能感興趣的試卷

你可能感興趣的試題

1.單項(xiàng)選擇題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

2.單項(xiàng)選擇題Failure to open the diesel engine test cocks after a long period of shutdown, prior to starting may result in （）

A.an air bound fuel system
B.damage to cylinder heads and pistons
C.excessive fuel injection
D.excessive air valve lift

3.單項(xiàng)選擇題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 nozzles

4.單項(xiàng)選擇題Critical speed in diesel engines occurs when engine torque pulsations become （）

A.opposed to the crankshaft rocking couple
B.resonant with the crankshaft natural frequency
C.critical fore and aft crankshaft vibrations
D.horizontal whipping motions of the crankshaft

5.單項(xiàng)選擇題Air receivers installed in starting air systems are to be （）.

A.cylindrical in shape with service connections located at the top and bottom
B.opened and made available for inspection during biannual inspections provided
C.with automatic drain traps for the removal of moisture
D.so installed as to make the drain connections effective under extreme conditions of trim