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1题：
The major cause of fuel pump and injection system problems is _____.
A.improper adjustments
B.contaminated fuel
C.kinked fuel lines
D.excessive engine vibration
第2题：
the pump supply pressure
the slope of the fuel cam
how the plunger is rotated
the number of sleeve segments engaged with the rack
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：
as close to the main engine as possible
as close to the main pump as possible
just before the fuel valve
just before the booster pump
第5题：
improper adjustment
contaminated fuel
kinked fuel lines
excessive engine vibration
第6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7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：
Improper lubrication
Air in the fuel system
Coated fuel lines
Excessive vibration
第10题：
high cost of fuel
serious fire hazard
possibility of pollution
poor combustion which will occur in that cylinder