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Fiat Grande Punto Factory Service Manual (2005-2012)22 · Fault diagnosis
22 · Diagnostics

Engine not running smoothly / (hesistant)

Make
Fiat
Model
Grande Punto Factory Service Manual
Year
2005–2012
Section
Engine › Engine not running smoothly / (hesistant)
Fault diagnosisEngine not running smoothly / (hesistant)

ENGINE NOT RUNNING SMOOTHLY / (HESISTANT)

1.2 8v, 1.4 8v

There is a (prolonged) fall in performance (flat spots) during acceleration

Test results
0PRELIMINARY CHECKSAll OKProblems encounteredOperation

First, check:

  • status of spark plugs and leads;
  • the condition of the air intake circuit
Move on to Step 1Spark plugs dirty or damaged

Replace the spark plugs

Op. 5510D10 SPARK PLUGS - R+R

Spark plug leads damagedReplace spark plug leads
Air intake circuit faultyEliminate the fault
1CHECK USING DIAGNOSTIC EQUIPMENTAll OKProblems encounteredOperation

Connect the Examiner diagnostic equipment to the diagnostic socket.

Check:

  • that there are no faults in the engine management control unit;
  • parameter plausibility
Move on to Step 2Error detected in the control unitContinue following the instructions for the diagnostic equipment
Parameter not consistentContinue following the instructions for the diagnostic equipment
2ROAD TEST USING DIAGNOSTIC EQUIPMENTAll OKProblems encounteredOperation

Carry out a road test reproducing the conditions in which the fault occurs, keeping the diagnostic equipment connected.

Check:

  • that there are no faults in the engine management control unit;
  • parameter plausibility
Move on to Step 3The sudden onset of an error in the control unit is detectedContinue following the instructions for the diagnostic equipment
Parameter not consistentContinue following the instructions for the diagnostic equipment
3FUEL PRESSURE CHECKAll OKProblems encounteredOperation

Carry out a road test, reproducing the conditions in which the problem occurs.

Check the fuel supply pressure

Op. 0510C10 FUEL SYSTEM - CHECK DELIVERY PRESSURE

Move on to Step 4Pressure not correct: obstructions in the fuel supply pipeRemove the obstructions in the fuel pipe, replace it if necessary
Pressure not correct: tank not sufficiently ventilatedRestore the tank ventilation
Pressure not correct: fuel pump electric circuit interruptedRestore fuel pump electric circuit
Pressure not correct: petrol pump damaged

Replace the petrol pump assembly

Op. 1040A70 SUBMERGED PUMP ASSEMBLY COMPLETE WITH LEVEL GAUGE CONTROL - R + R

4CHECK ON CORRECT OPERATIONAll OKProblems encounteredOperation
Check that the fault is no longer presentThe fault persists: control unit defective

Replace the control unit

Op. 1056B82 INJECTION/IGNITION SYSTEM E.C.U. (ONE) - R + R

Parts & tools for this job For 2005 Fiat Grande Punto

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