Internal combustion engine with fuel injectors

Claim 1

An internal combustion engine having cylinders and an intake passageway through which air is supplied to the cylinders, comprising: a main fuel injector; means for operating said main fuel injector so as to inject fuel into the intake passageway in a variable amount according to the engine operating condition; an auxiliary fuel injector; means for operating said auxiliary fuel injector so as to inject fuel into the intake passageway in a constant amount when activated irrespective of the engine operating condition; sensing means for sensing an engine operating parameter substantially representing the amount of intake air and for producing a signal in response to said parameter; control means, responsive to said signal, said control means including said means for operating said main fuel injector and said means for operating said auxiliary fuel injector, said control means also including additional means for operating both said main and auxiliary fuel injectors until the magnitude of said parameter decreases to reach a first predetermined value below which value said auxiliary fuel injector is stopped and for operating only said main fuel injector until the magnitude of said parameter increases to reach a second predetermined value in excess of which value both said main fuel injector and said auxiliary fuel injector operate, the amount of intake air at the first predetermined value being smaller than that at the second predetermined value; and means for starting a cold engine, which cold engine starting means includes an ignition switch having an "engine starting" position at which an engine starting motor of the engine is operated to rotate and an engine coolant temperature switch which is operatively connected between said ignition switch and said auxiliary fuel injector operating means, said temperature switch being put into its "ON" position when the engine coolant temperature is below a predetermined level, said auxiliary fuel injector operating means including means for operating said auxiliary fuel injector when said ignition switch is in its "engine starting" position and said engine coolant temperature switch is in the "ON" position.