Engine not running smoothly / (irregular operation)

Make: Fiat
Model: Idea Factory Service Manual
Year: 2003–2012
Section: Engine › Engine not running smoothly / (irregular operation)

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Fault diagnosisEngine not running smoothly / (irregular operation)

ENGINE NOT RUNNING SMOOTHLY / (IRREGULAR OPERATION)

1.4 16v

During driving, the engine misses and loses performance

0	PRELIMINARY CHECKS	All OK	Problems met	Operation
		Results of the tests
	Preliminarily check: the condition of the air filter the state of the spark plugs and leads; battery earth correctly fixed	Continue to Step 1	Filter element dirty, damaged or incorrectly fitted	Replace or refit filter element correctly
			Spark plugs dirty or damaged	Replace the spark plugs Op. 5510D10
			Spark plug leads damaged	Replace the spark plug leads Op. 5510D14
1	CHECK WITH DIAGNOSTIC EQUIPMENT	All OK	Problems met	Operation
	Connect the Examiner diagnostic equipment to the diagnostic socket. Check: that there are no faults in the engine management control unit; plausibility of all the parameters	Continue to Step 2	'Supply system' error detected	Continue according to the instructions for the See table Z50 MIXTURE STRENGTH ERROR
			'Upstream lambda sensor' error detected	Continue according to the instructions for the See table Z56 UPSTREAM LAMBDA SENSOR SIGNAL ERROR
			Another error dectected in the control unit	Continue following the instructions for the diagnostic equipment
			Inconsistent parameter	Continue following the instructions for the diagnostic equipment
2	ROAD TEST WITH DIAGNOSTIC EQUIPMENT	All OK	Problems met	Operation
	Road test the vehicle, reproducing the conditions in which the fault arises, keeping the diagnostic equipment connected. Check: that there are no faults in the engine management control unit; plausibility of all the parameters	Continue to Step 3	'Supply system' error detected	Continue according to the instructions for the See table Z50 MIXTURE STRENGTH ERROR
			'Upstream lambda sensor' error detected	Continue according to the instructions for the See table Z56 UPSTREAM LAMBDA SENSOR SIGNAL ERROR
			Sudden occurrence of another error in the control unit detected	Continue following the instructions for the diagnostic equipment
			Inconsistent parameter	Continue following the instructions for the diagnostic equipment
3	CHECK ON FUEL PRESSURE	All OK	Problems met	Operation
	Check, if necessary on the road (to reproduce the conditions in which the fault arises), the fuel supply pressure Op. 0510C10	Continue to Step 4	Pressure not correct: obstructions in fuel delivery pipe	Remove the obstructions in the fuel pipe, and if necessary replace it
			Pressure not correct: tank insufficiently ventilated	Restsore the tank ventilation
			Pressure not correct: fuel pump electrical circuit broken	Repair fuel pump electrical circuit
			Pressure incorrect: fuel pump damaged	Replace fuel pump assembly Op. 1040A70
4	CHECK AIR CONDITIONING SYSTEM	All OK	Problems met	Operation
	Road test the vehicle and check whether the fault is affected by whether or not the air conditioner is switched on	Continue to Step 5	Fault present only with the air conditioner on	Continue according to the instructions for the See table L10 CLIMATE CONTROL NOT COOLING
5	CHECK ON CORRECT OPERATION	All OK	Problems met	Operation
	Check that the fault is no longer present	End of diagnosis	Fault persists: control unit faulty	Replace control unit Op. 1056B82

1.3 JTD 16v

During driving, the engine misses and loses performance

0	PRELIMINARY CHECKS	All OK	Problems met	Operation
		Results of the tests
	Check, in order: the condition of the air intake circuit that there are no faults in the air filter whether the diesel pipes are leaking that the battery earth is correctly fixed that there is no water, petrol, paraffin or dirt in the fuel tank and filter that there no obstructions in the exhaust system	Continue to Step 1	Fault in air intake circuit	Repair the air intake circuit
			Air filter blocked	Replace the filter element Op. 1048A14
			Leak from diesel pipes	stop the leak
			Loose battery earth terminal	Restore the correct fixing of the earth cable
			Presence of water, petrol, paraffin or dirt detected	Clean the tank and pipes and replace the filter element Op. 1048A14
			Obstruction in the exhaust system	Replace the damaged system component
1	CHECK WITH DIAGNOSTIC EQUIPMENT	All OK	Problems met	Operation
	Connect the Examiner diagnostic equipment to the diagnostic socket and check: that there are no errors in the control unit absence of errors between the engine control unit and the ABS control unit, particularly error U1706	Continue to Step 2	Presence of error P0093	Continue to Step 2
			For the presence of one of the following errors:P0262, P0265, P0268, P0271	Continue to Step 3
			Presence of error P0704	Continue to Step 4
			Presence of one of the following errors: P0120, P0220, P0226	Continue to Step 5
			Presence of one of the following errors: P0101, P1102	Continue to Step 6
			Presence of communication errors between the engine control unit and ABS control unit	Check wiring continuity See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT
			Presence of other errors	Continue according to the instructions for the diagnostic equipment
2	HIGH RESSURE CIRCUIT CHECK	All OK	Problems met	Operation
	With the Examiner tester connected to the tester input check: Check that the diesel pressure parameter is as described in the test 1060D the correct operation of the pressure regulator by means of active diagnostics absence of leaks in high pressure circuit the correct operation of the injectors through active diagnosis	Continue to Step 3	Diesel pressure parameter incorrect	Continue to Step 3
			Pressure regulator defective	Replace the pressure regulator Op. 1060E50
			Leaks in high pressure circuit	Restore system seal
			Faulty injector	Replace the damaged injector Op. 1060F10
3	INJECTOR HIGH PRESSURE CHECK	All OK	Problems met	Operation
	Check, as described in the test See Test 1060C Injector high pressure fuel circuit check, that diesel leaks from the injector recirculation connections are small and about the same as one another.	Continue to Step 4	Consistent leak from one injector	Replace the injector Op. 1060F10
4	CHECK CLUTCH SWITCH	All OK	Problems met	Operation
	With the Examiner tester connected, check: correct positioning of switch on clutch pedal correct operation of clutch switch	Continue to Step 5	Incorrect switch position	Position the switch correctly
		Continue to Step 5	Faulty switch operation	Replace switch Op. 1060G42
5	CHECK ACCELERATOR PEDAL POTENTIOMETER	All OK	Problems met	Operation
	Check the correct operation of the accelerator pedal potentiometer as described in the test See Test 1068AB Check operation of accelerator pedal potentiometer	Continue to Step 6	Incorrect potentiometer operation	Replace potentiometer Op. 1068A20
		Continue to Step 6	Electrical wiring defective	Renew the wiring See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT
6	FLOW METER CHECK	All OK	Problems met	Operation
	Check the correct operation of the flow meter as described in the test See Test 1060GB Check on operation of air flow meter	Continue to Step 7	Faulty flow meter operation	Replace the flow meter Op. 1060G10
7	CHECK HIGH PRESSURE PUMP	All OK	Problems met	Operation
	Connect the Examiner tester and carry out a road test. Check the diesel pressure changes in accordance with rpm/load.	Continue to Step 8	Unstable rail pressure caused by defective high pressure pump.	Replace high pressure pump Op. 1060E10
8	CHECK ON CORRECT OPERATION	All OK	Problems met	Operation
	Check that the fault is no longer present	End of diagnosis	Fault persists: control unit faulty	Replace control unit Op. 1060G80

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Parts & tools for this job For 2003 Fiat Idea

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