Fuel injection control means for internal combustion engines

Claim 1

An engine intake system including first intake passage means leading to combustion chamber means, second intake passage means substantially separated from said first intake passage means and leading to said combustion chamber means, shut-off valve means provided in said second intake passage means for closing said second intake passage means under a light load engine operation, first fuel injection valve means provided in said first intake passage means, second fuel injection valve means provided in said second intake passage means, fuel injection control means for operating said first fuel injection valve means under the light load engine operation and for operating said first and second fuel injection valve means under a heavy load engine operation to provide a metered quantity of fuel supply, said control means including compensating means for momentarily changing the quantity of fuel supply when operating condition is changed between the light load and heavy load engine operations by an amount which varies in accordance with engine speed whereby a stepwise change in engine output torque can be avoided, wherein said compensating means is means for momentarily increasing the quantity of fuel supply when the second fuel injection valve means is started to operate for the heavy load engine operation and is means for increasing the quantity of fuel supply by an amount which increases in response to a decrease in engine speed.