Patent ID: 7806104

Claim:
A control apparatus for an internal combustion engine including a low-pressure pump supplying fuel of low pressure and a high-pressure pump supplying fuel of high pressure to a fuel injection mechanism from a fuel tank, said internal combustion engine including a first fuel injection mechanism injecting fuel into a cylinder and a second fuel injection mechanism injecting fuel into an intake manifold, and fuel can be supplied from said high-pressure pump and said low pressure pump to said first fuel injection mechanism, said control apparatus comprising: a determination unit determining that an operation state of said internal combustion engine is in an idle state, and a control unit controlling said internal combustion engine, wherein said control unit controls said low-pressure pump, said high-pressure pump and said first and second fuel injection mechanisms depending upon which of three or more predetermined idle states said idle state belongs to based on a temperature of said internal combustion engine, said control unit effects any one of control such that said high-pressure pump is stopped and control such that a discharge pressure from said high-pressure pump is reduced when determination is made that the operation state is in said idle state, and said high-pressure pump being connected to a return line, the high-pressure pump and the return line being connected without a high-pressure delivery pipe therebetween.