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

Check of serviceability of functioning of the fuel pump, measurement of pressure of fuel

See preventions at the beginning of the Section Dropping Pressure in a power supply system.


General checks

Make sure available of a gasoline tank of enough fuel. Examine fuel lines on existence of signs of leaks.

Make sure that the fuel pump really works. Cock the parking brake and ask the assistant to include ignition, having turned a key in position of ON, - in a gasoline tank the characteristic sound of the working pump has to be heard (the pump has to work about two seconds during which the required rise in pressure in a power supply system is carried out).

The sound of the working pump is well heard through an open mouth of the fuel tank. If the pump works regularly, however, there are suspicions on violation of serviceability of functioning of a power supply system, measure the pressure developed naosy.


If the pump does not turn on, pass to check of a condition of its electric chain (see the Head Onboard electric equipment). Check the corresponding safety locks and the relay, make sure of serviceability of giving of food on the pump socket. Estimate quality of grounding.

If food moves regularly, and quality of grounding is not broken, replace the pump (see the Section Removal and installation of the fuel pump).

Verification of the pressure head characteristic of the fuel pump

Check of pressure of fuel requires the special manometer with a scale of wide range and a transitional nozzle for connection of the manometer to system of injection.


 PERFORMANCE ORDER

1. Dump pressure in a power supply system (see the Section Dropping Pressure in a power supply system).

2. Disconnect the final line from the fuel filter, connect the three-running union to which connect the manometer between the filter and the fuel highway. Track reliability of tightening of hose collars.

3. Switch off everything consumers of the electric power and turn a key in the ignition lock in position of ON. There has to be a 5-second turning on of the fuel pump, - consider the indication of the manometer. Compare the received result to requirements of Specifications.
4. Start the engine and warm up it on single turns up to the normal working temperature. Consider the indication of the manometer and compare its value given in Specifications. Disconnect from pressure regulator the vacuum line (see the Section Removal and installation of the regulator of pressure of fuel), - pressure has to increase to the value stipulated in paragraph 4.
5. If the taken readings do not exceed the limit of the admissible ranges stipulated in Specifications, therefore, the system functions regularly, otherwise, execute the following checks:

a) If pressure is excessively high, check serviceability of giving of depression for the fuel pressure regulator. Change of turns of the engine has to lead to depression fluctuations. If depression takes place, check passability and a condition of a hose and a tube of the line of return of fuel. If the returnable line as it should be, replace pressure regulator;
b) With excessively low pressure, check a state and passability of the fuel filter and a fuel pipe going from the fuel highway to a gasoline tank. If during survey it is not possible to reveal any violations, start the engine and slowly press the returnable line. If pressure increases over 3.0 kgfs/cm 2, replace pressure regulator (see the Section Removal and installation of the regulator of pressure of fuel).

Do not allow increase of pressure over 4.2 kgfs/cm 2. If pressure is still not enough, replace the fuel pump (see the Section Removal and installation of the fuel pump);

6. Kill the engine, having left ignition included. Continue to watch indications of the manometer within about 5 more minutes - pressure has to decrease slowly. If pressure falls excessively quickly, execute the following checks:

a) Without switching off ignition, press the line of supply of fuel on the site between the three-running union and the fuel tank, then switch off ignition, - if pressure falls quickly, therefore leaks through an injection injector(s) take place;
b) Again include ignition and press the giving line, this time, on the site, between the union and the fuel highway. Switch off ignition, - bystry pressure drop demonstrates violation of functioning of the control valve of the submersible fuel pump.
7. Having finished check, dump fuel pressure (see the Section Dropping Pressure in a power supply system) and disconnect the manometer.