Caravelle L4-156 2.6L SOHC (1985)
Carburetor: Description and Operation
Fig. 2 Mikuni feedback carburetor assembly
1984 EXC. CALIFORNIA MODELS & ALL 1985
The Mikuni feedback carburetor, Fig. 2, is a two barrel down draft carburetor designed for electronic fuel control and closed loop operation.
With a closed loop system of mixture control, this carburetor provides optimum air/fuel control during all ranges of engine operation. Fuel metering
is accomplished through the use of three solenoid valves that reduce or add fuel to the engine.
The fuel flow through the valves is controlled by the length of time electrical current is supplied to the solenoids. The solenoids operate at a fixed
frequency generated by the electronic control unit. By varying the amount of time that the solenoid is energized during each duty cycle, the air/fuel
mixture delivered to the engine can be precisely controlled. The duty cycle applied to the solenoid is controlled by the electronic control unit in response
to signals received from various sensors.
There are eight basic systems in the feedback carburetor: fuel inlet, primary metering, secondary metering accelerator pump, choke, jet mixture,
enrichment and fuel cut-off. The first five systems are basically the same as those on the non-feedback carburetor while the last three are unique to the
feedback carburetor.
