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Fiat Croma Factory Service Manual (2005-2010)22 · Fault diagnosis

Fiat
Croma Factory Service Manual (2005-2010)
Fault diagnosis
Engine
Engine not running smoothly / (hesistant)

22 · Diagnostics

Engine not running smoothly / (hesistant)

Make: Fiat
Model: Croma Factory Service Manual
Year: 2005–2010
Section: Engine › Engine not running smoothly / (hesistant)

‹ Prev Gear engagement sensitivity poor Next › Engine not running smoothly / (losing power)

Fault diagnosisEngine not running smoothly / (hesistant)

ENGINE NOT RUNNING SMOOTHLY / (HESISTANT)

1.8, 2.2

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

0	PRELIMINARY CHECKS	All OK	Problems encountered	Operation
		Results of the tests
	First, check: status of spark plugs and leads; the condition of the air intake circuit	Move on to Step 1	Spark plugs dirty or damaged	Replace the spark plugs Op. Op. 5510D10 SPARK PLUGS - R+R
			Spark plug leads damaged	Replace spark plug leads
			Air intake circuit faulty	Eliminate the fault
1	CHECK USING DIAGNOSTIC EQUIPMENT	All OK	Problems encountered	Operation
	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 detected	See table Z50 ERRORE TITOLO MISCELA
			Another error detected in the control unit	Continue following the instructions for the diagnostic equipment
			Parameter not consistent	Continue following the instructions for the diagnostic equipment
2	ROAD TEST USING DIAGNOSTIC EQUIPMENT	All OK	Problems encountered	Operation
	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	The sudden onset of an error in the control unit is detected	Continue following the instructions for the diagnostic equipment
		Move on to Step 3	Parameter not consistent	Continue following the instructions for the diagnostic equipment
3	FUEL PRESSURE CHECK	All OK	Problems encountered	Operation
	Carry out a road test, reproducing the conditions in which the problem occurs. Check the fuel supply pressure Op. Op. 0510C10 FUEL SYSTEM - CHECK DELIVERY PRESSURE	Move on to Step 4	Pressure not correct: obstructions in the fuel supply pipe	Remove the obstructions in the fuel pipe, replace it if necessary Op. Op. 1040B32 FRONT FUEL DELIVERY LINE - R.R.
			Pressure not correct: tank not sufficiently ventilated	Restore the tank ventilation
			Pressure not correct: fuel pump electric circuit interrupted	Restore fuel pump electric circuit See See E5030 PETROL ENGINES ELECTRONIC MANAGEMENT
			Pressure not correct: petrol pump damaged	Replace the petrol pump assembly Op. Op. 1040A70 SUBMERGED PUMP ASSEMBLY COMPLETE WITH LEVEL GAUGE CONTROL - R + R
4	CHECK ON CORRECT OPERATION	All OK	Problems encountered	Operation
	Check that the fault is no longer present		The fault persists: control unit defective	Replace the control unit Op. Op. 1056B82 INJECTION/IGNITION SYSTEM E.C.U. (ONE) - R + R Search for the fault starting from another symptom

‹ Prev Gear engagement sensitivity poor Next › Engine not running smoothly / (losing power)

Parts & tools for this job For 2005 Fiat Croma

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