Problems with the diesel engine fuel injection pump are usually caused by（）

A.check cylinder lubrication prior to starting engine
B.connect exhaust gas analyzers to determine engine efficiency
C.pressure test cylinder heads to check for leaks
D.remove moisture accumulations from cylinder prior to starting

A.constantly decreasing as engine load increase
B.constantly increasing as the amount of supercharging increases
C.approximately equal to exhaust manifold pressure at all times
D.approximately equal to atmospheric pressure at all times

A.prolonged maintenance intervals
B.improved atomization
C.greater fuel economy
D.incomplete combustion