Fuel injection valves should be taken out, cleaned, and lifting checked every （）.

A . exhaust valves B . mechanical lubricators C . cooling water pumps D . fuel injection pum

A . broken down B . stuck C . oil leakage D . carbonized

A . Bad combustion of the fuel B . Bad atomization of the fuel C . Liquid contaminants D . Solid contaminant

A . improper adjustment B . contaminated fuel C . kinked fuel lines D . excessive engine vibratio

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

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

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

A . smoother engine operation B . advanced fuel ignition C . increased fuel economy D . reduced engine power

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

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

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

A . because B . though C . since D . until

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

A . be jammed B . be opened C . be seated D . be broke

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

A . the steering B . the driven gear C . the turning gear D . the timing gear

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

A . Common-rail injection B . Air injection C . Jerk pump injection D . Distribution injectio

A . lower compression pressures B . overheating without smoking C . failure to start D . a run away without load

A . improper adjustments B . contaminated fuel C . kinked fuel lines D . excessive engine vibratio

A . water leakage B . steam leakage C . oil leakage D . air leakage

A . fuel oil pressure B . a cam operated follower C . a spring-loaded pressure plate D . timing gears keyed to the crankshaft

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

A . assist in a quick cutoff of fuel injection B . allow oil backflow from the injector to the helix C . reduce fuel oil pressure between injection strokes D . meter the quantity of fuel delivered