The fuel supplies system is one of the most important sub-systems of diesel engine

whose capability directly affects the engender of air admixture

engine’s dynamical quality

jump-start quality

noise and pollution of the environment etc.The fuel injection timing in diesel engines directly decides whether the fuel supplies system can normal work.Aimed at the different fuel injection condition in the different pressure

the external pipe oil signal measuring method and proceed pretreatment and second signal disposition are applied

in which pick-up the diagnosis eigenvalue

thereby different diagnosis result of different work condition is give

because of the fuel pressure wave signal’s repetition perfect

the characteristics of amplitude at each urn of the same work sect changes small

therefore

the characteristics of amplitude applied to diagnose the fuel supplies system of diesel engine is effective and feasible.