leaking delivery valve
excessive bearing end play
plugged injector spray hole
increased plunger stroke
第1题：
An increase in the fuel injection pump discharge pressure can be caused by a/an _______.
A.leaking delivery valve
B.excessive bearing end play
C.plugged injector spray hole
D.increased plunger stroke
第2题：
The amount of fuel delivered by a helical plunger fuel injection pump is controlled by ______.
A.varying the pump discharge pressure
B.varying the pump return pressure
C.rotation of the pump plunger
D.rotation of the pump barrel
第3题：
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 the cylinder injection valves
B.gasket surfaces of the fuel oil filters
C.discharge fittings of the fuel injector pumps
D.suction side of the fuel oil transfer pump
第4题：
improper adjustment
contaminated fuel
kinked fuel lines
excessive engine vibration
第5题：
quantity of fuel injected is decreased
quantity of fuel injected will always be increased
start of injection is advanced
duration of injection will always be greater
第6题：
An increase in rotor clearances in a rotary pump will ______.
A.increase discharge pressure
B.decrease pump capacity
C.decrease pump cavitation
D.decrease reaction ring clearance
第7题：
changes the position of the fuel inlet ports
changes the length of the pump stroke
varies the quantity of fuel delivered
varies the compression of the delivery valve spring
第8题：
Which of the following problems is the main source of fuel pump and injection system malfunctions?
A.Improper lubrication
B.Air in the fuel system
C.Coated fuel lines
D.Excessive vibration
第9题：
deliver proper fuel quantity to the injection nozzle
provide rapid fuel injection cutoff
control fuel quantity entering the pump body
control fuel pressure delivered to the combustion chamber
第10题：
Improper lubrication
Air in the fuel system
Coated fuel lines
Excessive vibration