3233014 - D01 ENGINE NOT RUNNING SMOOTHLY / (HESISTANT)

There are decreases in performance, possibly prolonged, during acceleration
Results of the tests
0PRELIMINARY CHECKSAll OKProblems metOperation

First check:

  • that there is no water, other fluid or dirt in the fuel tank
  • the state of the spark plugs and leads
  • correct fixing of battery earth
 Continue to Step 1 Presence of dirt in the fuel tank Clean the fuel tank Op.   1040A10 
Spark plugs dirty or damaged Clean or replace the spark plugs Op.   5510D10 
Spark plug leads damaged Replace spark plug leads Op.   5510D14 
Battery earth lead not correctly fixed Restore correct fixing Op.   5530B22 
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 2 An error is detected in the control unitContinue following the instructions for the diagnostic equipment
Lack of dialogue with the control unit Restore 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 active diagnosis on the:

  • vapour recovery solenoid valve
  • Injectors
 Continue to Step 3 Solenoid valve connection faulty Restore the connection of the solenoid valve with the control unit ( See   E5030  PETROL ENGINE ELECTRONIC MANAGEMENT )
Solenoid valve faulty Replace the solenoid valve Op.   1080E24 
Injector connections faulty Restore injector connections with control unit, ( See   E5030  PETROL ENGINE ELECTRONIC MANAGEMENT )
Injectors faulty Replace injectors Op.   1056B70 
3COIL CHECKAll OKProblems metOperation
2.5 V6Using the diagnostic equipment (Examiner or other instruments) carry out the active diagnosis of the injectorsCheck that the potentiometer is correctly calibrated Continue to Step 4 Ignition coil connections faulty Restore the connection for the coils with the control unit ( See   E5030  PETROL ENGINE ELECTRONIC MANAGEMENT )
Ignition coils faulty Replace ignition coils Op.   5510C14 
Accelerator potentiometer: incorrectly setRestore the operation of the potentiometer
1.6 TS 1.8 TS [d]

Check, in order:

 Continue to Step 4 Connections not correctRestore connections
Ignition coils faulty Replace ignition coils Op.   5510C14 
4CHECKING LAMBDA SENSORAll OKProblems metOperation
Check that the Lambda sensor is working properly See Test   1080BB  Check operation of fuel vapour recovery solenoid valve Continue to Step 5 Lambda sensor not working properly Replace the Lambda sensor Op.   1080B60 
5CHECKING ALTERNATORAll OKProblems metOperation

Check::

  • that the alternator voltage regulator is working properly
  • the connections between the alternator and the battery
 Continue to Step 6 Voltage regulator not working properlyReplace the voltage regulator
Connections not correct Restore the connections See   E5010  STARTING AND RECHARING ) or replace the damaged components
6CHECKING AIR CIRCUITAll OKProblems metOperation

Check::

  • the condition and seal of the air supply circuit
  • that the air filter is correctly fitted
 Continue to Step 7 Circuit component damagedReplace component (See Assembly 1048A)
7CHECKING FUEL PRESSUREAll OKProblems metOperation
Check the fuel supply pressure Op.   0510C10  Continue to Step 8 Pressure not correct Replace the fuel pump assembly Op.   1056B70 
8CHECKING CYLINDER COMPRESSIONAll OKProblems metOperation
Carry out the cylinder compression test Op.   0510A10  Continue to Step 9 Compression values not correct Restore the correct cylinder compression, for example, by checking the seal of the injectors Op.   1056B70  and cylinders (see OVERHAULING ENGINE, Subassembly 1004)
9CHECKING CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persistsSearch for the fault starting from another symptom'