Fuel Injection - BOSCH AFC - JAPANESE Models: Description: Notes

NOTE: The Bosch AFC Fuel Injection system is used on all models and variations may exist between model applications with the addition of auxiliary control systems. This article covers the Bosch AFC system in general, with manufacturer's differences noted.

The Bosch Air Flow Controlled (AFC) fuel injection system is an electronically controlled system operated by incoming air flow. The AFC fuel injection system also contains a feedback system which measures oxygen content of exhaust gases and maintains the air/fuel ratio at about 14.7:1.

The fuel injection system consists of an electric fuel pump, fuel pressure regulator, fuel damper (except Toyota models), fuel injectors, Electronic Control Unit (ECU) and air flow meter. In addition, an air temperature sensor, throttle switch, coolant temperature sensor (cylinder head temperature sensor on Datsun/Nissan models), oxygen sensor, catalytic converter, auxiliary air valve and electrical relays are used.

All models except 200SX and 280ZX Turbo are equipped with a cold start system which consists of an auxiliary air valve, cold start injector and thermo time switch. A dash pot is installed on the throttle chamber of 200SX models with automatic transmission to prevent engine stalls due to abrupt closing of throttle valve.

The electronic control system of 280ZX Turbo models controls emission control system, idle speed control system, fuel injection system, spark timing and fuel pump operation. Under normal service procedures, it is not necessary to adjust idle mixture, idle speed or ignition timing.