2888337 - D10 ENGINE IDLE IRREGULAR

The engine is not running smoothly when idling; in particular, it does not maintain a constant, regular value as the load varies (e.g. when electrical devices are switched on, etc.).
Results of the tests
0PRELIMINARY CHECKSAll OKProblems metOperation

Preliminarily check:

  • the state of the spark plugs and leads
  • condition of air filter
  • the condition of the air intake circuit
Continue to Step 1Spark plugs dirty or damagedClean or replace the spark plugs Op.     5510D10
Spark plug leads damagedReplace the spark plug leads Op.     5510D14
Filter element dirty or damagedReplace the filter element Op.     1048A14
Air intake circuit component damaged Replace the component (see Assembly 1048A)
1CHECKING WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Connect the diagnostic equipment (Examiner or other instruments) to the diagnostic socket

Check

  • that there are no faults in the engine management control unit
  • the plausibility of all the parameters.
Continue to Step 2An error is detected in the control unit Continue according to the instructions for the diagnostic equipment
Lack of dialogue with the control unitRestore the connection between the engine management control unit and the diagnostic connector See     E5030 PETROL ENGINE ELECTRONIC MANAGEMENT
2IDLE CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Using the diagnostic equipment (Examiner or other iinstruments) carry out active diagnosis on the idle actuatorContinue to Step 3Idle actuator connection defectiveRestore connection between idle actuator and control unit, See     E5030 PETROL ENGINE ELECTRONIC MANAGEMENT
Idle actuator defectiveReplace the idle actuator Op.     1056B56
3CHECKING LAMBDA SENSORAll OKProblems metOperation
Check that the Lambda sensor is working properlyContinue to Step 4Lambda sensor not working properlyReplace the Lambda sensor Op.     1080B60
4VAPOUR RECOVERY SYSTEM CHECKAll OKProblems metOperation
Check the condition and the seal of the vapour recovery pipesContinue to Step 5Pipes obstructed or have extremely small holesRestore the vapour recovery pipes and replace if necessary (see Assembly 1080E)
5CHECK VACUUM PIPEAll OKProblems metOperation
Check condition and fitting of vacuum pipeContinue to Step 6Pipe fitted incorrectly or bentRefit correctly
Pipe damagedReplace the vacuum pipe Op.     3330D24
6CHECK ON FUEL PRESSUREAll OKProblems metOperation
Check the fuel supply pressure Op.     0510C10 Continue to Step 7Pressure not correctReplace the fuel pump assembly Op.     1040A70
7CHECK ON TIMINGAll OKProblems metOperation
Check that the engine timing is correctContinue to Step 8Timing not correctRestore the correct engine timing Op.     1032B14
8CHECK ON CYLINDER COMPRESSIONAll OKProblems metOperation
Carry out the cylinder compression test Op.     0510A10 Continue to Step 9Compression values not correctRestore the correct cylinder compression, e.g by checking the injector seal Op.     1056B70
9CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persists