Fuel system for compression ignition engine

Claim 1

Apparatus comprising: an air breathing internal combustion engine having an intake manifold and a compressor for delivering air to said intake manifold at a pressure level generally increasing as a direct function of increasing engine power level; means for delivering fuel to said engine at a pressure level which increases as a direct function of increasing engine rpm and increasing operator demand; pressure modulating means connected between said fuel delivery means and said engine having a cavity responsive to a pressure signal for varying the pressure level of fuel from said fuel delivery means as a direct function of the level of said pressure signal; conduit means connecting said pressure varying means to the pressure existing in said intake manifold; and means for forming an orifice in series flow relation to said conduit means and means forming a housing between said orifice and said cavity, said housing means and said cavity forming a chamber for producing a delay of transient increases in pressure signals from said manifold to said pressure varying means, thereby delaying the increase in fuel rate to said engine.