Carburetor - HITACHI 2-Bbl: Description

Carburetor is a 2-barrel downdraft design with primary and secondary throttle system. A choke valve and idle circuit are used in primary system only. Both primary and secondary venturies have main fuel nozzles.

A mechanical accelerator pump and a vacuum operated power valve are used for increased fuel requirements. An anti-dieseling switch or solenoid valve is used to stop fuel flow in idle circuit (on some models) when ignition switch is turned off. Federal Nissan models use a cold enricher system; other models use an electric automatic choke.

Some models use an altitude compensator device to maintain optimum air/fuel ratio at higher altitudes.

Nissan uses an air/fuel ratio control solenoid control valve in conjunction with ECC (electronic-controlled carburetors) on California models. Federal models use an idle speed control actuator.