LPG-engine fuel control apparatus

摘要

LPG decompressed in a regulator 3 is fed as primary fuel into an intake passage 6 from a carburetor 9, and is fed as supplementary fuel to the intake passage 6 from an injector 11. An ECU 4 controls a control variable for the injector 11 to cause an air/fuel ratio detected in an oxygen sensor 53 to be a stoichiometric air/fuel ratio. In an idle operation, an optimum state of the control variable with respect to a target value is output from a monitor terminal 57 and is monitored, and an adjusting screw 37 in a slow passage 36 is operated and adjusted to cause the control variable to be the target value. An adjustment range for the control variable is set into two stages through operation of the test terminal 56. The ECU 4 controls an output pattern of a monitor terminal 57 in individual adjustment ranges at each stage, according to whether or not the control variable falls within the adjustment range.