Nissan Maxima QX

since 1993 release

Repair and operation of the car

Nissan Maxima QX
+ Cars of the Nissan Maxima brand
+ Maintenance instruction
+ Settings and routine maintenance
+ Engine
+ Cooling systems, heating
- Power supply system and release
   General information
   Dropping pressure in a power supply system
   Check of serviceability of functioning of the fuel pump, measurement of pressure of fuel
   Check of a state and replacement of fuel lines and their nipple connections
   Removal and installation of the fuel pump
   Check of a state and replacement of the sensor of fuel consumption
   Removal and installation of the fuel tank
   Cleaning and repair of the fuel tank - general information
   Removal and installation of assembly of the air cleaner
   Removal, installation and adjustment of a cable of an accelerator
   System of electronic injection of fuel (EFI) - the general information
   Check of serviceability of functioning of system of injection
   Check of a state and replacement of the case of a throttle
   Removal and installation of the regulator of pressure of fuel
   Removal and installation of the fuel highway and injectors of injection
   Check and adjustment of turns of idling
   System of release - the general information
+ Engine electric equipment
+ Control systems of the engine
+ Transmission
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment

System of electronic injection of fuel (EFI) - the general information

All cars considered in the present manual are equipped with system of the electronic distributed injection of fuel (EFI). The injection is made consistently to inlet ports of each of combustion chambers as ignition and in the quantity determined by the current requirements of the engine. About one injector of injection is the share of each of cylinders of the engine. Injectors are mounted on assembly of the inlet pipeline which top section represents the delivery camera providing optimum conditions for air supply to the inlet highway and dosages with its removable throttle camera (the throttle case).

The main component (think-tank) of system of injection is the onboard processor called also by the module of management of functioning of the power unit (RSM). RSM analyzes the data which are continuously arriving on it from various information sensors and counts composition of air-fuel mix optimum at the moment. The system provides also automatic compensation of changes of such external factors as height of position of the car above sea level, loading and turns of the engine.

Supply of fuel to the highway of system is provided by means of a high-pressure submersible electric gasoline pump. Being pumped over via the fuel filter, fuel on system of fuel pipes comes to the fuel highway of the EFI system.

The structure of assembly of the fuel highway included the electric injectors making the dosed fuel injection directly to inlet ports of combustion chambers of the engine. Besides injectors assembly of the fuel highway switched on also the fuel pressure regulator which is constantly supporting a fuel pressure at the set level. Excess of the fuel coming to the highway on a returnable fuel pipe is taken away back in a gasoline tank.

Injectors represent electromagnetic valves of the constant course. The main components of an injector are: the operating electromagnet, a plunger and the needle valve. All listed details are placed in the general case. When passing electric current on the solenoid coil the needle valve is slightly opened, fuel under a pressure fills a cavity of the case of an injector and vypryskivatsya through a nozzle in the combustion chamber of the corresponding cylinder. The amount of injectable fuel is defined by duration of time of opening of the valve, i.e., duration of giving of tension on the electromagnet coil. For the purpose of the restriction of current missed through injectors the electrical wiring of chains of the last turns on resistors.

Lasting inclusions of injectors RSM operates. In memory of the module basic values of time of opening of valves for various combinations of the entering parameters (engine turns, quantity and temperature of the soaked-up air) are put. Necessary information arrives on the module in the form of signals from the corresponding sensors of the engine.