2.5.6. Possible malfunctions of the L-Jetronic system, their reason and methods of elimination

Malfunctions 1 — 8

  1. The cold engine is not started.
  2. The cold engine is started and "becomes deaf".
  3. The hot engine is not started.
  4. The complicated launch of the cold engine.
  5. The complicated launch of the hot engine.
  6. The engine works unstably during warming up.
  7. Violation of the mode of idling.
  8. The engine is started and "becomes deaf".

malfunction No.

Cause of defect
Elimination method

1

2
3

4

5
6
7
8

X

 

X

         

There is no fuel in the fuel tank

To fill in fuel in a tank

X

             

The fuel pump is faulty

To check operation of the pump, if necessary to replace

X

X

X

X

X

X

X

X

The fuel filter is littered

To wash out the filtering grid or to replace the filter

 

X

 

X

 

X

X

X

The drain pipeline is deformed or littered

To correct or blow a fuel-supply line

       

X

 

X

X

Elevated pressure of fuel

To check operation of the regulator of pressure, if necessary to replace

X

X

 

X

 

X

X

X

The lowered fuel pressure in system

To check operation of the regulator of pressure, if necessary to replace

X

X

 

X

X

X

The increased operating pressure

To check operation of the regulator of the operating pressure, if necessary to replace

 

X

X

X

X

X

X

The lowered operating pressure

To check operation of the regulator of the operating pressure, if necessary to replace

X

X

X

X

X

X

X

X

Leakage of nozzles of injection

To replace nozzles

             

X

Injection nozzles are partially littered

To replace nozzles

X

X

X

       

The starting nozzle does not work

To check a starting nozzle, wires and their connections

X

   

X

       

Leakage of a starting nozzle

To replace a nozzle

             

X

The thermal timer is faulty

To replace the relay

     

X

       

The sensor of temperature of cooling liquid is faulty

To check wires and their connections, if necessary to replace the sensor

X

X

X

X

X

Adjustment of a butterfly valve is broken

To adjust a starting position of a butterfly valve

X

     

X

X

The valve of additional giving of a vozdu is not closed

To check the valve, if necessary to replace

       

X

   

X

Leakage of the airgiving cap and/or the measuring instrument of amount of air

To check inlet system, if necessary to replace

     

X

X

X

 

X

Weakening of an inhaling of nozzles of injection

To tighten nozzles

           

X

Leakage of system of a vypsuk of the fulfilled gases

To eliminate leakage of system

             

X

Spark plugs are faulty

To replace spark plugs

X

X

X

X

X

X

The ignition coil is faulty

To replace the ignition coil

X

X

         

The switchboard is faulty

To replace the switchboard

X

X

         

Break in wires of system of ignition

To replace the damaged wires

               

Wrong regulation of the moment of ignition

To replace the switchboard

               

Vacuum hoses are damaged

To replace the damaged hoses

             

X

The ignition advancing regulator is faulty

To replace the ignition sensor distributor

X

X

X

X

X

   

X

Wrong installation of the moment of ignition

To adjust the ignition moment

X

X

X

X

X

X

X

X

The engine is subject to repair

 

X

X

X

X

     

Use of gasoline with low octane number

To apply fuel only with the required octane number

X

     

X

X

X

Adjustment of idling of the engine is broken

To adjust idling

Malfunctions 9 — 17

  1. Backfires in the final pipeline.
  2. The engine works with interruptions at dispersal.
  3. The engine works with interruptions on forcibly single to the course.
  4. Interruptions in operation of the engine on all modes.
  5. The engine does not develop full capacity.
  6. The increased fuel consumption.
  7. Violation of adjustment of idling and contents WITH in the fulfilled gases.
  8. Knock of inlet and final valves at dispersal.
  9. The increased content of hydrocarbons and oxides of nitrogen in the fulfilled gases.
malfunction No.
Cause of defect
Elimination method

9

10
11
12
13

14

15
16
17
                 

There is no fuel in the fuel tank

To fill in fuel in a tank

                 

The fuel pump is faulty

To check operation of the pump, if necessary to replace

X

   

X

X

X

X

The fuel filter is littered

To wash out the filtering grid or to replace the filter

       

X

X

X

X

The drain pipeline is deformed or littered

To correct or blow a fuel-supply line

         

X

X

X

Elevated pressure of fuel

To check operation of the regulator of pressure, if necessary to replace

X

       

X

   

The lowered fuel pressure in system

To check operation of the regulator of pressure, if necessary to replace

X

X

   

X

X

X

X

The increased operating pressure

To check operation of the regulator of the operating pressure, if necessary to replace

   

X

X

X

 

X

X

X

The lowered operating pressure

To check operation of the regulator of the operating pressure, if necessary to replace

X

X

X

X

X

 

X

X

X

Leakage of nozzles of injection

To replace nozzles

X

   

X

X

X

X

X

Injection nozzles are partially littered

To replace nozzles

X

X

X

X

X

X

The starting nozzle does not work

To check a starting nozzle, wires and their connections

   

X

           

Leakage of a starting nozzle

To replace a nozzle

X

       

X

X

X

The thermal timer is faulty

To replace the relay

                 

The sensor of temperature of cooling liquid is faulty

To check wires and their connections, if necessary to replace the sensor

X

X

X

X

X

X

Adjustment of a butterfly valve is broken

To adjust a starting position of a butterfly valve

X

             

The valve of additional giving of a vozdu is not closed

To check the valve, if necessary to replace

X

X

         

X

X

Leakage of the airgiving cap and/or the measuring instrument of amount of air

To check inlet system, if necessary to replace

X

X

   

X

X

X

X

Weakening of an inhaling of nozzles of injection

To tighten nozzles

         

X

X

X

X

Leakage of system of a vypsuk of the fulfilled gases

To eliminate leakage of system

     

X

   

X

X

X

Spark plugs are faulty

To replace spark plugs

X

X

X

X

X

The ignition coil is faulty

To replace the ignition coil

X

X

X

     

X

The switchboard is faulty

To replace the switchboard

X

X

X

     

X

Break in wires of system of ignition

To replace the damaged wires

X

X

X

X

X

Wrong regulation of the moment of ignition

To replace the switchboard

X

X

X

X

       

Vacuum hoses are damaged

To replace the damaged hoses

X

X

X

X

       

The ignition advancing regulator is faulty

To replace the ignition sensor distributor

X

X

X

X

X

X

X

Wrong installation of the moment of ignition

To adjust the ignition moment

X

X

X

X

X

X

X

X

X

The engine is subject to repair

 

X

X

X

   

X

Use of gasoline with low octane number

To apply fuel only with the required octane number

         

X

X

X

X

Adjustment of idling of the engine is broken

To adjust idling