2888332 - D01 ENGINE NOT RUNNING SMOOTHLY / (HESISTANT)

The engine does not run smoothly in all conditions (load, speed, etc.).In particular, it "hesitates", i.e. there is a lack of or delayed response from the accelerator pedal
Results of the tests
0PRELIMINARY CHECKSAll OKProblems metOperation

Preliminarily check:

  • that there is no water, other fluid or dirt in the fuel tank
  • the state of the spark plugs and leads
  • engine wiring earth correctly fixed
  • battery earth correctly fixed
  • positive lead between battery and alternator correctly fixed
Continue to Step 1Presence of dirt in the fuel tankClean the fuel tank Op. 1040A24
Spark plugs dirty or damagedClean or replace the spark plugs Op.   5510D10 
Spark plug leads damagedReplace the spark plug leads Op.   5510D14 
Earth leads incorrectly fixedRestore battery earth lead Op.   5530B22 
Battery positive earth incorrectly fixedRestore battery positive lead Op.   5530B26 
1CHECK 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
  • plausibility of all the parameters
Continue to Step 2An error is detected in the control unitContinue 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 ).
2ACTIVE DIAGNOSIS WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation

Using the diagnostic equipment (Examiner or other instruments) carry out the active diagnosis of:

  • vapour recovery solenoid valve
  • electro-injector
  • coils
Continue to Step 3Faulty vapour recovery solenoid connectionRestore the connection of the solenoid valve with the control unit ( See   E5030  PETROL ENGINE ELECTRONIC MANAGEMENT )
Faulty vapour recovery solenoidReplace the solenoid valve Op. 1080E28
Injector connections faultyRestore the connection of the injectors with the control unit, ( See   E5030  PETROL ENGINE ELECTRONIC MANAGEMENT )
Ignition coils faulty Replace the injectors Op.   1056B70 
Ignition coils faulty Restore the connection for the coils with the control unit, See   E5030  PETROL ENGINE ELECTRONIC MANAGEMENT
Ignition coils faulty Replace the ignition coils Op.   5510C14 
3FUEL PRESSURE CHECKAll OKProblems metOperation
Check the fuel supply pressure Op.   0510C10  Continue to Step 4Pressure not correctReplace the fuel pump assembly Op.   1040A70 
4LAMBDA SENSOR CHECKAll OKProblems metOperation
Check that the Lambda sensor is working properly Continue to Step 5Lambda sensor not working properlyReplace the Lambda sensor Op.   1080B60 
5AIR CIRCUIT CHECKAll OKProblems metOperation

Check:

  • the condition and seal of the air supply circuit, and the filter in particular
Continue to Step 6Circuit component damagedReplace the component (see Assembly 1048A)
Air filter incorrectly fittedRefit the air filter correctly Op.   1048A14 
Air cleaner dirty or partially blockedReplace the air filter Op.   1048A14 
6CYLINDER COMPRESSION CHECKAll OKProblems metOperation
Carry out the cylinder compression test Op.   0510A10  Continue to Step 7Compression values not correctRestore the correct cylinder compression, e.g by checking the seal of the injectors Op.   1056B70  and the cylinders if necessary
7CHECKING CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persistsSearch for the fault starting from another symptom'