Nissan Primera

1990-1992 of release

Repair and car operation

Nissan Primera
+ Nissan Primera brand Cars
+ Current leaving and service
+ Engine
+ cooling and heating Systems
- Power supply system and production of the fulfilled gases
   + Power supply system of carburetor engines
   - Power supply system of injector engines
      Multiitem system of injection (SR20DE engine)
      System of the central injection of fuel (SR20Di engine)
      Butterfly valve cable
      Vacuum hoses
   + System of production of the fulfilled gases
+ System of electric equipment of the engine
+ Manual transmission, differential and main transfer
+ Automatic transmission
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
+ Appendices


Multiitem system of injection (SR20DE engine)

The provision of separate elements of system of injection of fuel and ignition system in an impellent compartment of the car with the SR20DE engine

1 — an adsorber
2 — the valve of additional air
3 — injection gates
4 — a regulator of pressure of fuel
5 — the sensor of provision of a butterfly valve
6 — the fuel filter
7 — the switching valve, idling adjustment

8 — the sensor of temperature of cooling liquid
9 — an air regulator
10 — the resistor
11 — the transistor
12 — the ignition coil
13 — the sensor of an angle of rotation of the crankshaft
14 — a measuring instrument of a stream of air

If to open a cowl, it is possible to see usual for the modern car a set of hoses, wires and other details which belong or to injection system, or to ignition system. On an illustration it is shown on the impellent compartment showing an arrangement of basic elements of both systems above. Let's shortly stop on work of some elements. The sensor of an angle of rotation of the crankshaft (13) is established in the distributor of ignition and is a basic element of both systems. The sensor traces number of turns of the engine and position of pistons and sends the corresponding signal to a monitor, for management of injection, ignition and other functions. The sensor has a rotor disk and a tokovy contour. The disk has 360 shliyets, each of which corresponds to crankshaft turn on 1 °, and also 4 other shliyets who serve for 4 cylinders and are located at distance 180 °. In that contour are established sacred and photo cells. When the rotor passes between sacred and photo cells, shlitsa on a disk interrupt the light signal transferred from a light-emitting diode to a photo cell. Without going into details, it is possible to tell that impulses which will be transformed by that contour are thus developed and sent in the form of signals on an electronic monitor. The last processes them and carries out the corresponding adjustments in injection and ignition systems.

  1. The measuring instrument of a stream of air (14) is near the air filter and measures amount of soaked-up air. Measurement is carried out as follows: the electronic monitor receives an electric signal which corresponds to heat given by a heating element, a blown stream of soaked-up air. When soaked-up air proceeds in the inlet pipeline and thus blows in a heating element, air receives heat developed by this element. The quantity of heat depends on amount of air. As the temperature of a heating element is automatically regulated on a certain value, it is necessary to submit a current on a heating element to maintain temperature of a constant element. On the basis of electric changes the monitor defines amount of air.
  2. The sensor of temperature of the engine (8) is behind the oil filter in specified illustrations below a place. The sensor traces temperature of cooling liquid and in the form of a signal hands over information in an electronic monitor. The sensor is equipped with a termistor reacting to change of temperature. Electric resistance of a termistor decreases at increase in temperature.
Position of the sensor of temperature of cooling liquid (1) near the oil filter (2).
  1. The sensor of provision of a butterfly valve (5) reacts to movement of a pedal of gas. It will transform the provision of a butterfly valve to a signal and transfers it in an electronic monitor. The provision of idling of a butterfly valve when the device receives the corresponding signal is defined by a monitor, and it, for example, stops supply of fuel.
  2. Gates of injection (3) have small being switched valves. When the electronic device sends a signal to the injection gate, the winding of the gate involves a needle and fuel is injected into the inlet pipeline. As fuel also is long injected is defined by a monitor.
  3. The regulator of pressure of fuel (4) supports in system constant pressure 3.0 bar. As the amount of injected fuel depends on duration of injection, pressure should be supported at the set level.
  4. The signal proceeding from a monitor arrives on the intensifying cascade (11) which operates primary that contour of the coil of ignition. The high voltage acts in film from a secondary contour of the coil. Ignition coil not standard type.
  5. The regulator of air (9) regulates an air stream bypassing a butterfly valve, if the engine cold or during warming up on fast idling. The regulator reacts to temperature and depending on it changes cross-section section of the channel. In a place (2) there is a valve of additional air which works with the operating valve (7). These interdependent elements receive signals from a monitor and regulate engine idling on a preset value. On an illustration it is shown below, how the switching module looks. On the specified place there is a screw of adjustment of idling.

Type of the valve of additional air and accompanying components

1 — a bolt of adjustment of H.H
2 — the valve of additional air
3 — the switching valve
  1. The sensor of speed is established in a speedometer and will transform a signal of speed to impulses which move in a monitor. To support number of turns of idling when the engine is exposed to additional loading at servoupravleniye work, in the pipeline of a high pressure of system of a steering the sensor of pressure of oil which gives out a loading signal on a monitor is established. It informs the valve of additional air, on necessary increase of number of turns of idling depending on the size of loading.
  2. On the block of cylinders the sensor of a detonation of the engine is located. If the engine because of a detonation is subject to vibration, it will be transformed by the sensor to a signal of tension which moves in a monitor.
  3. The fuel filter (6) is in the metal case to sustain a high pressure of fuel. To the filter from above and from below it is connected on one hose. The filter sits in a spring latch. Before replacing the filter (it is recommended through each 40000 km or every 2 year), it is necessary to lower pressure of fuel in system to avoid the fuel razbryzgivaniye. Establish only the filter corresponding to Specifications.
  4. The adsorber with absorbent carbon (1) serves for described in the Section of System of decrease in toxicity of the fulfilled gases for the carburetor engine. All elements relating to system of ignition are described in Head System of electric equipment of the engine.
  5. The fuel pump is in a fuel tank. The monitor turns on the fuel pump in some seconds after ignition inclusion, for simplification of start of the engine. When the monitor receives a signal "180" from the sensor of position of the crankshaft, he knows that the engine rotates and turns on the pump. If this signal is impossible, the engine is disconnected and the pump is established in such mode at which tension of the battery is saved and safety is provided. The monitor starts the pump via the separate relay.
  6. On cars with the catalyst in an exhaust system it is established a lambda probe. It carries out measurement of the content of oxygen in the fulfilled gases and changes the relation of amount of fuel and air according to it.

Works on system

At carrying out any works on system at which are disconnected топливопроводы, at first it is necessary to reduce pressure of fuel. Thus act as follows:


  1. Open a cover of a box of safety locks and take out the safety lock represented on an illustration. It is a safety lock of the fuel pump. Now start the engine. After a while it will decay, as will not receive fuel. Two-three more times turn the crankshaft a starter to reduce all pressure. At once insert a safety lock into place. Now it is possible to disconnect all fuel hoses between the engine and a body.
The provision of a safety lock of the fuel pump (1) in a box of safety locks.
  1. At all the others, first of all electric works which demand existence of necessary knowledge observe the following security measures:
  2. Use only the 12-volt battery.
  3. Never disconnect battery cables on the working engine.
  4. Never disconnect cables of gates of injection on the working engine.
  5. Never put to injection gates the devices connected directly to the battery.
  6. Measuring instrument of a stream of air very sensitive and with it it is necessary to address as appropriate. It is not subject to dismantling. It also should not be washed out by any liquid.
  7. The valve of additional air is not subject to dismantling.
  8. Even small not tight places in system of absorption of air can influence operation of the engine.
  9. The electronic monitor is not subject to repair.
  10. At start of the engine do not squeeze out a gas pedal. Do not increase engine turns right after start and before switching off.
  11. If in a tank there is no fuel, do not include a starter for engine start as the fuel pump should not work without fuel.
  12. Always connect cable tips of a monitor according to the description. Bad connection can lead to formation of a power surge and because of it to damages of the coil of ignition and other elements. Hold the main cable distributing a minimum in 10 mm from other cables to avoid external impact on cable connections. All cable plaits should be dry. Always switch off ignition and disconnect a weight cable from the battery before weakening any connection.