Fuel Injection System: Description

The Nissan Throttle Body Fuel Injection system is a electronically controlled system with 2 fuel injectors mounted in the throttle body. The Electronic Control Unit (ECU) of the Electronic Concentrated Engine Control System (ECCS) controls the amount of fuel injected into intake manifold by varying the pulse time that fuel injectors remains "on".

In addition to containing the 2 fuel injection nozzles, the throttle body include a hot wire airflow meter. This airflow meter measures the intake airflow by taking part of the entire flow.

The fuel injection system consists of an electric fuel pump, fuel damper, fuel filter, fuel pressure regulator, throttle body unit, mixture heater and ECU. In addition, this system uses input from various sensors. These sensors include a crank angle sensor, cylinder head temperature sensor, airflow meter, oxygen sensor and throttle position sensor. Also used are an air injection valve, idle up solenoid, EGR solenoid and electrical relays.

NOTE: Only primary sub-systems which affect fuel system operation will be covered in this article. For further information, see appropriate article in EXHAUST EMISSION SYSTEMS section.