Pressure reduction in the supply system

1. Remove fuse no. 9 (fuel pump fuse) from right fuse box

  • 2. Start the engine and let it run until the fuel line runs out of fuel. After that, the engine will stall.
  • 3. Replace the fuse.
  • 4. Replace damaged chain guides.
  • 5. After that, you can disconnect the fuel lines.

Replacing the Mass Air Flow Sensor

1. Disconnect the wire from the "negative" terminal of the battery.

Checking and replacing the DMRV sensor ZMZ-406

2. Disconnect connector 1 from mass air flow sensor 3.

Loosen the clamps, disconnect the air supply hoses 2 and remove the sensor 3.

3. Install the new sensor in reverse order.

Checking the Mass Air Flow Sensor

  • 1. Remove the mass air flow sensor.
  • 2. Connect a voltmeter to pins "2" and "Z" of the sensor connector. Apply a constant current of 12 V to contacts "1" and "5" (n" to contact <5>, and <-> to ((1). In this case, the voltmeter should show a voltage of 1.3-1, 4 V.

Then briefly close contacts "4" and "5" between each other. At the same time, the voltmeter should show a voltage of about 8 V, and the platinum thread should become red-hot.

If at least one of these conditions is not met, replace the sensor.

Adjusting the content of carbon monoxide (CO) in exhaust gases

Adjusting the ZMZ-406 CO

  • 1. The adjustment is made on a warm engine (coolant temperature 80-90 ° C) with a working ignition system and nominal gaps between the spark plug electrodes.
  • 2. The content of CO and CH in the exhaust gases should be within: 0.7–0.9% CO and 1200 million –1 CH at a crankshaft speed of (800±50) min –1 ; not more than 0.5% CO and 600 million –1 CH at a crankshaft speed of (3150±50) million –1 .
  • 3. If the CO content is above the specified limits, adjust the CO content with screw 1 on the mass air flow sensor.

Turning the screw clockwise increases the CO content and counterclockwise decreases it. In this case, the content of CH will also be adjusted.

If it is not possible to adjust the content of CO and CH within the specified limits, it is necessary to check the serviceability of the elements of the integrated microprocessor-based engine control system.

Replacing the accelerator cable

  • 1. Disconnect the wire from the "Negative" terminal of the battery.
  • 2. Loosen nut 1 and pull accelerator cable 2 out of sector 3 of choke control.

ZMZ-406 throttle cable replacement

3. Slide gland 1 off the cable tip, completely unscrew nut 2 from the cable tip, pull tip 3 of the cable sheath out of the bracket and pull it up out of the bracket through the cable slot.

Remove the tip 3 from the cable, removing it from the outer 4 and inner shells of the cable.

ZMZ-406 throttle cable replacementZMZ-406 throttle cable replacement

  • 4. Remove the outer 1 and inner sheaths of the cable from the tip 2 on the bulkhead.
  • 5. Remove cotter pin 1 from pin and remove pin 2. Slide oil seal 4 and remove bracket 3.

ZMZ-406 throttle cable replacement

  • 6. Pull the cable through the lug on the bulkhead into the passenger compartment.
  • 7. Install the new accelerator cable in reverse order and adjust it.

Adjusting the throttle cable

1. Loosen the nut 1 fastening the cable 2 on sector 3.

ZMZ-406 throttle cable adjustment

2. Loosen the nut 2 of the adjusting bolt 1 between the upper 4 and lower 3 accelerator pedal levers.

ZMZ-406 throttle cable adjustment

3. From the side of sector 3, the throttle valve is extended cable 1 to the stop. In this case, the upper lever 5 of the accelerator pedal must rest against the buffer 4 on the bracket.

Tighten nut 2 securing the cable to the sector. In this case, the throttle valve must be completely closed.

ZMZ-406 throttle cable adjustment

  • 4. Pull the upper lever 4 of the pedal towards you as far as it will go. While holding the upper lever 4 of the pedal in this position, turn the lower lever 3 of the pedal until it stops on the mat and tighten the nut 2 of the adjusting bolt 1
  • 5. When properly adjusted, with the pedal fully released, the throttle should be fully closed, and the upper pedal arm should rest against the buffer on the bracket.

With the pedal fully depressed, the throttle should be fully open and the lower pedal arm should rest against the mat.

ZMZ-406 throttle cable adjustment

6. You can correct the position of the cable by moving the tip 1 of the shell in the bracket, loosening the tightening of the nut 2. After adjusting the nut 2, tighten it.

Throttle
Removal

  • 1. Disconnect the wire from the "negative" terminal of the battery.
  • 2. Disconnect the accelerator cable from the throttle sector
  • 3. Disconnect connector 1 with wires from the throttle position sensor.

Loosen the clamps and disconnect the idle speed control 2 and crankcase ventilation hoses 3.

ZMZ-406 throttle replacement

4. Loosen the clamps and disconnect the throttle heating hoses 1, having previously marked them.

Immediately plug the hoses with plugs to prevent loss of coolant.

Remove the four mounting bolts 2 and remove the throttle 3 with the gasket.

ZMZ-406 throttle replacement

5. If it is necessary to remove the throttle position sensor 2, unscrew the two screws 1 securing it.

ZMZ-406 throttle replacement

Idle speed regulator replacement

1. Disconnect the wire from the "negative" terminal of the battery.

Replacing the idle speed regulator ZMZ-406

2. Loosen the clamps and disconnect hoses 1 and 2 from the regulator 5. Disconnect the block with wires from the connector 4 of the regulator.

Remove the two mounting bolts 3 and remove the regulator. Remove regulator 5 from clamp 6.

3. Install new idle control in reverse order.

Checking the idle speed control

  • 1. Remove idle speed control.
  • 2. Apply 12 V DC to the middle pin of the regulator connector and alternately to the side pins

This should rotate the damper to open or close the inlet port.

If this does not happen, then the regulator is faulty and needs to be replaced.

Replacing nozzles

  • 1. Reduce the pressure in the fuel system if the engine has just been stopped.
  • 2. Disconnect the wire from the "negative" terminal of the battery.
  • 3. Remove receiver.
  • 4. Loosen the clamps and disconnect the fuel supply hose 1 from the fuel line 3 of the engine. Disconnect the fuel drain hose 4 from the pressure reducing valve.

Disconnect the pads with wires from the connectors 5 of the four injectors.

Replacing ZMZ-405 injectors

5. Remove the injector from the engine fuel line. The nozzle is fixed in the opening of the fuel line only with the help of a sealing ring.

Unscrew the two fastening bolts 2 and carefully remove the fuel line 3 of the engine, removing the nozzles from the holes in the intake pipe.

Injectors are fixed in the intake pipe holes only with O-rings.

Replacing ZMZ-405 injectors

6. Install the new injector in reverse order.

Checking the injectors

Checking ZMZ-405 injectors

1. to check the tightness of the injector valve, lower the atomizer 1 of the injector into a container with gasoline or erosin and apply compressed air at a pressure of 0.3 MPa (0.03 kgf/cm).

If air bubbles come out of the nozzle atomizer, then the nozzle valve is leaky and the nozzle needs to be replaced.

2. to check the health of the injector solenoid winding, apply a direct current of 12 V to the injector connector. In this case, a characteristic click should be clearly audible, which indicates the opening of the injector valve.

If this does not happen, then the nozzle is faulty and must be replaced. This test can be carried out without removing the nozzle from the vehicle.

3. The resistance of the injector solenoid winding can be checked with an ohmmeter by connecting it to the injector connector pins. Resistance should be in the range of 15.5-16 ohms.

If the resistance value is not within the specified limits, replace the nozzle.

Replacing the pressure reducing valve

  • 1. Reduce the pressure in the fuel system if the engine has just been stopped.
  • 2. Disconnect the wire from the "negative" terminal of the battery.
  • 3. Remove the engine fuel line.

Replacement of pressure reducing valve ZMZ-406

4. Disconnect fuel drain hose 1 and vacuum hose 4 from pressure reducing valve 3.

Remove two fastening bolts 2 and remove the pressure reducing valve 3 from the engine fuel line.

5. Install the new valve in reverse order.

Replacing and checking the timing sensor

1. Disconnect the wire from the "negative" terminal of the battery.

Replacing the ZMZ-406 crankshaft sensor

2. Disconnect the sensor wire block 3 located behind the engine intake pipe.

Remove bolt 2 and remove sensor 1.

Check the resistance of the sensor coil with an ohmmeter, it should be between 850 and 900 ohms.

If the resistance value is not within the specified limits, replace the sensor.

Install the sensor in reverse order.

For normal operation of the sensor, the gap "a" between sensor 1 and synchronization disk 4 must be within 1.0–1.5 mm.