Mazda 626

1991-1998 of release

Repair and operation of the car



Mazda 626

+ 1. Maintenance instruction
+ 2. Maintenance
+ 3. Engines
+ 4. Heating and ventilation
- 5. Fuel system
   + 5.1. Nikki 30/34 carburetor
   - 5.2. Power supply system (l engines 1,6 and 1,8)
      5.2.1. Introduction
      5.2.2. Technical characteristics
      5.2.3. Release of pressure from a power supply system
      5.2.4. The fuel pump/pressure in a power supply system
      5.2.5. Fuel tubes and connections
      5.2.6. Removal and installation of the fuel pump
      5.2.7. Fuel level sensor
      5.2.8. Fuel tank
      5.2.9. Air filter
      5.2.10. Accelerator rope
      + 5.2.11. System of electronic injection of fuel
   + 5.3. Power supply system (l engines 2,0 and 2,5)
+ 6. Exhaust system
+ 7. Transmissions
+ 8. Coupling and half shafts
+ 9. Brake system
+ 10. Running gear
+ 11. Body
+ 12. Electric equipment
+ 13. Electrical circuitries
+ 14. Useful tips


5.2.4. The fuel pump/pressure in a power supply system

GENERAL INFORMATION

Identification of plugs of the main relay of electronic injection of fuel (model 1990-1994 of year of release)


Identification of plugs of the relay of disconnection of a chain / fuel pump

Identification of plugs of the relay of the fuel pump (model after 1995 of release)

Check of the fuel pump

PERFORMANCE ORDER
1. Connect the F/P or GND plugs of the diagnostic socket a wire.
2. Uncover a jellied mouth of the fuel tank.
3. Turn a key in the ignition lock in position of ON.
4. The fuel pump has to turn on.
5. If is not present, check presence of tension of the accumulator on the socket of connection of the fuel pump. Measure tension between a wire of B/P of the socket of connection of the pump and "weight". It has to equal 12 Volts.
6. If is not present, check a safety lock of system of electronic injection of fuel and the relay of the pump.
7. If everything is all right, check existence of conductivity between the B/P and B plugs of the socket of connection of the pump.

8. If there is no conductivity, check grounding of the pump and replace the pump if it is necessary.

Check of pressure of fuel
9. Release pressure from a power supply system and connect the manometer by means of a tee to the fuel supply hose going from the fuel filter to the engine. Measure pressure created by the fuel pump near the fuel filter.
10. Execute the operations described in points 1-3 and check fuel pressure.

11. Start the engine, leave it to work in the mode of idling and again check fuel pressure.

12. Kill the engine and check that pressure of fuel did not fall below minimum admissible. If pressure falls probably in pressure regulator, the fuel pump or injectors there is a leak.
Check of the regulator of pressure of fuel
13. Check fuel pressure. Connect the vacuum pump to the regulator of pressure and check that pressure of fuel decreased at increase in depression.
14. Connect a vacuum hose to the regulator and start the engine. Disconnect a hose and check that pressure of fuel increased. If fuel pressure when idling too high, check whether there is no leak in a branch pipe of air supply or an inlet collector. If is not present, replace the fuel pressure regulator.
15. If pressure of fuel is lowered, press a hose of the return pipeline. If pressure does not increase, so the fuel pump is faulty or the fuel supply tube is littered.
16. If fuel pressure too high, check whether the return pipeline is littered. If is not present, replace the fuel pressure regulator.
Check of the main relay, relay of disconnection of a chain (early models) and relay of the fuel pump (late models) of system of electronic injection of fuel
Check of tension
17. Remove the main relay of system of an electronic vsprysk of fuel (it is specified by an arrow fig. at the left) and check that at inclusion of ignition on plugs A and B of the main relay there was accumulator tension (fig. on the right).
18. Check that at inclusion of ignition on plugs of light green and white-red wires (early models) or between plugs of white-red wires (late models) accumulator tension was the relay of the fuel pump / disconnection of a chain.
Main relay of system of electronic injection of fuel

19. Check that the relay clicked at inclusion / switching off of ignition.

20. Check existence of conductivity between relay plugs A and B. When giving tension on plugs A and B, conductivity between plugs C and D has to appear.
21. Check resistance between plugs of the relay of the fuel pump / disconnection of a chain:
– between STA and E1 – 21–43 Ohms;
– between In and Fc – 109–226 Ohms;
– between plugs B and Fp there should not be a conductivity.
The relay of the fuel pump (model after 1995 of release)

22. Check that between plugs A and B there was a conductivity. When giving tension on plugs A and B, conductivity between the C and D plugs has to appear. Replace the relay if it is necessary.




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