194002396 - D002 ENGINE NOT RUNNING SMOOTHLY / (LOSING POWER)

Prolonged performance reductions occur under constant load and speed conditions.
Results of the tests
0PRELIMINARY CHECKSAll OKProblems encounteredOperation

First, check:

  • status of spark plugs and leads;
  • condition of the air filter;
  • the condition of the air intake circuit;
  • no obstructions at the catalyzer
Move on to Step 1Spark plugs dirty or damagedReplace the spark plugs Op.    Op. 5510D10 SPARK PLUGS - R+R
Spark plug leads damagedReplace spark plug leads
Air intake circuit faultyEliminate the fault
Catalytic converter obstructedReplace the exhaust manifold Op.    Op. 1072C16 EXHAUST MANIFOLD WITH CATALYTIC CONVERTER - R.R.
1CHECK USING DIAGNOSTIC EQUIPMENTAll OKProblems encounteredOperation
Connect the diagnostic test equipment (Examiner or other instruments) to the tester input.

Check:

  • that there are no faults in the engine management control unit;
  • parameter plausibility
Move on to Step 2"Fuel system" error detectedSee table    Z50 ERRORE TITOLO MISCELA
"Misfire" error detectedSee table    Z53 ERRORE MANCATE ACCENSIONI
Another error 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 3"Fuel system" error detectedSee table    Z50 ERRORE TITOLO MISCELA
"Misfire" error detectedSee table    Z53 ERRORE MANCATE ACCENSIONI
Another error detected in the control unitContinue following the instructions for the diagnostic equipment
Parameter not consistentContinue following the instructions for the diagnostic equipment
3FUEL PRESSURE ROAD TESTAll OKProblems encounteredOperation
Carry out a road test and check the fuel supply pressure Op.    Op. 0510C10 FUEL SYSTEM - CHECK DELIVERY PRESSUREunder the conditions in which the fault occursMove on to Step 4Fuel pressure too low: pipes obstructedEliminate the constrictions
Fuel pressure too low: valve obstructedReplace the fuel cap Op.    Op. 1040A40 PLUG FOR FUEL FILLER PIPE - R + R
Fuel pressure too low: regulator blockedReplace the pump assembly Op.    Op. 1040A70 SUBMERGED PUMP ASSEMBLY COMPLETE WITH LEVEL GAUGE CONTROL - R + R
Fuel pressure too low: pump defectiveReplace the pump assembly Op.    Op. 1040A70 SUBMERGED PUMP ASSEMBLY COMPLETE WITH LEVEL GAUGE CONTROL - R + R
Fuel pressure too low: filter blockedReplace the pump assembly Op.    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 defectiveReplace the control unit Op.    Op. 1056B82 INJECTION/IGNITION SYSTEM E.C.U. (ONE) - R + RSearch for the fault starting from another symptom