D03 Engine working irregularly (sawing)

Make: Alfa Romeo
Model: 147 Factory Service Manual
Year: 2000–2002
Section: Engine › D03 Engine working irregularly (sawing)

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Fault diagnosisD03 Engine working irregularly (sawing)

D03 Engine working irregularly (sawing)

Step	Test procedure	Result	Action
0	PRELIMINARY CHECKS First check: the condition of the air filter the state of the spark plugs and leads; battery earth correctly fixed Wiring diagram E1010 POWER SUPPLY	OK	Move onto step 1
		Filter element dirty, damaged or incorrectly fitted	Replace or refit filter element correctly Op. 1048A14 End of diagnosis
		Spark plugs dirty or damaged	Replace the spark plugs Op. 5510D10 End of diagnosis
		Spark plug leads damaged	Replace spark plug leads End of diagnosis
1	CHECK WITH DIAGNOSTIC EQUIPMENT Connect the diagnostic equipment (Examiner or other instruments) to the diagnostic socket Verify: that there are no faults in the engine management control unit the plausibiilty of the parameters	OK	Move onto step 2
		'Supply system' error detected	See table Z50 MIXTURE STRENGTH ERROR End of diagnosis
		'Misfire' error detected	See table Z56 UPSTREAM LAMBDA SENSOR SIGNAL ERROR End of diagnosis
		Another error detected in the control unit	Continue following the instructions for the diagnostic equipment End of diagnosis
		Incoherent parameter	Continue following the instructions for the diagnostic equipment End of diagnosis
2	ROAD TEST WITH DIAGNOSTIC EQUIPMENT Road test the vehicle, reproducing the conditions in which the fault arises, keeping the diagnostic equipment connected. Verify: that there are no faults in the engine management control unit the plausibiilty of the parameters	OK	Move onto step 3
		'Supply system' error detected	See table Z50 MIXTURE STRENGTH ERROR End of diagnosis
		'Misfire' error detected	See table Z56 UPSTREAM LAMBDA SENSOR SIGNAL ERROR End of diagnosis
		Another error detected in the control unit	Continue following the instructions for the diagnostic equipment End of diagnosis
		Incoherent parameter	Continue following the instructions for the diagnostic equipment End of diagnosis
3	CHECK FUEL PRESSURE Check, if necessary on the road (to reproduce the conditions in which the fault arises), the fuel supply pressure Op. 0510C10	OK	Move onto step 4
		Incorrect pressure: obstructions in the fuel supply pipe	Remove the obstructions in the fuel pipe, and if necessary replace it Op. 1040A30 End of diagnosis
		Incorrect pressure: tank not sufficiently ventilated	Restore tank ventilation End of diagnosis
		Pressure incorrect: fuel pump electrical circuit interrupted	Repair fuel pump electrical circuit Wiring diagram E5030 PETROL ENGINES ELECTRONIC CONTROL End of diagnosis
		Pressure incorrect: fuel pump damaged	Replacement of petrol pump assembly Op. 1040A70 End of diagnosis
4	CHECK ON AIR CONDITIONING Road test the vehicle and check whether the fault is affected by whether or not the air conditioner is switched on	OK	Move onto step 5
4		Fault present only when air conditioner is on	See table L10 CLIMATE CONTROL UNIT DOES NOT COOL End of diagnosis
5	CORRECT OPERATION CHECK Check that the fault is no longer present	OK	Incorrect selection of diagnostic procedure
5		The fault persists: control unit defective	Replace control unit Op. 1056B82 Incorrect selection of diagnostic procedure

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Parts & tools for this job For 2000 Alfa Romeo 147

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