22 · Diagnostics

Engine idle irregular

Make: Fiat
Model: Idea Factory Service Manual
Year: 2003–2012
Section: Engine › Engine idle irregular

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Fault diagnosisEngine idle irregular

ENGINE IDLE IRREGULAR

1.4 16v

The engine is not running smoothly when idling; in particular, it does not maintain a constant, regular value as the load varies (e.g. when electrical devices are switched on)

0	PRELIMINARY CHECKS	All OK	Problems met	Operation
		Results of the tests
	Preliminarily check: the state of the spark plugs and leads; the condition of the air filter the condition of the air intake circuit	Continue to Step 1	Spark plugs dirty or defective	Replace the filter element Op. 5510D10
			Leads defective	Replace the spark plug leads Op. 5510D14
			Air filter blocked	Replace the filter element Op. 5510D10
			Fault in air intake circuit	Restore the correct operation of the intake circuit
1	CHECK WITH DIAGNOSTIC EQUIPMENT	All OK	Problems met	Operation
	Connect the diagnostic equipment (Examiner or other instruments) 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
			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	IDLE ACTUATOR CHECK	All OK	Problems met	Operation
	Check that the system carries out the correct idle learning procedure	Continue to Step 3	Irregular idling	Carry out the idle learning procedure correctly
3	PETROL VAPOUR RECOVERY SYSTEM CHECK	All OK	Problems met	Operation
	Check the condition and seal of the petrol vapour recovery pipes	Continue to Step 4	Air seepage	Restore the correct seal
		Continue to Step 4	Pipe from canister to solenoid broken	Replace the pipe
4	PETROL VAPOUR RECOVERY SOLENOID VALVE CHECK	All OK	Problems met	Operation
	Carry out active diagnosis of solenoid	Continue to Step 6	Solenoid not working	Continue to Step 5
5	SOLENOID VALVE ELECTRICAL CIRCUIT CHECK	All OK	Problems met	Operation
	Check supply and earth of petrol vapour recovery solenoid	Continue to Step 6	Solenoid valve faulty	Replace the solenoid valve Op. 1080E28
6	BRAKE SERVO AND PIPE CHECK	All OK	Problems met	Operation
	Check condition of: brake servo vacuum pipes; brake servo See Test 3330DA Check operation of brake servo vacuum circuit and vacuum unit	Continue to Step 7	Brake servo pipe defective	Replace the pipe
		Continue to Step 7	Brake servo defective	Replace the brake servo/pump assembly Op. 3330D02
7	CHECK ON FUEL PRESSURE	All OK	Problems met	Operation
	Check the fuel supply pressure Op. 0510C10	Continue to Step 8	Insufficient fuel pressure: pipe obstructed	Eliminate the blockage; if necessary replace the pipe
			Low fuel pressure: clogged filter	Replace the pump assembly Op. 3330D02
			Insufficient fuel pressure: regulator out of calibration	Replace the pump assembly Op. 3330D02
			Low fuel pressure: defective pump	Replace the pump assembly Op. 3330D02
8	CHECK ON TIMING	All OK	Problems met	Operation
	Check that the timing is correct Op. 0510A20	Continue to Step 9	Timing not correct	Restore the correct timing
9	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

The engine is not running smoothly when idling; in particular, it does not maintain a constant, regular value as the load varies (e.g. when electrical devices are switched on)

0	PRELIMINARY CHECKS	All OK	Problems met	Operation
		Results of the tests
	Check: the condition of the air intake circuit condition and correct operation of the air filter	Continue to Step 1	Air intake circuit ducts blocked	Repair the air intake circuit
		Continue to Step 1	Air filter blocked	Replace the filter element Op. 1048A14
1	CHECK WITH DIAGNOSTIC EQUIPMENT	All OK	Problems met	Operation
	Connect the diagnostic equipment (Examiner or other instruments) to the diagnostic socket check that there are no errors in the control unit plausibility of all the parameters Carry out: electrical E.G.R. valve fault diagnosis injectors active diagnosis Check the EGR is operating correctly, in particular that the EGR is not stuck open	Continue to Step 2	Presence of one of the following errors: P0101, P1102	Continue to Step 4
			EGR faulty	Check the continuity of the wiring See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENTand replace the EGR valve if necessary Op. 1080C10
			EGR valve blocked open	Restore correct operation of EGR system
			Injector faulty (incorrect atomization)	Check the injector wiring and, if necessary, replace the damaged injector Op. 1060F10
			Presence of other errors in the control unit	Continue following the instructions for the diagnostic equipment
2	CHECK ON FUEL FILTER	All OK	Problems met	Operation
	Check the operation of the fuel filter	Continue to Step 3	Presence of water, petrol, paraffin or dirt detected	Clean the tank and pipes and replace the diesel filter cartridge Op. 1044B20
3	CHECK FUEL PUMP	All OK	Problems met	Operation
	Use an Examiner to check fuel pump power uptake is correct by performing the test See Test 1040AA Check supply voltage' and absorption current'	Continue to Step 4	Pump defective	Replace the pump Op. 1040A70
4	CHECK FLOW METER	All OK	Problems met	Operation
	Use an Examiner to check fuel pump power uptake is correct by performing the test See Test 1060GB Check on operation of air flow meter	Continue to Step 5	Flow meter signal too high	Replace the flow meter Op. 1060G10
5	CHECK ON INJECTORS	All OK	Problems met	Operation
	Check that the injectors are working properly by carrying out the active diagnosis using the Examiner diagnostic equipment	Continue to Step 6	Injector faulty (incorrect atomization)	Check the injector wiring and, if necessary, replace the damaged injector Op. 1060F10
6	PRESSURE REGULATOR CHECK	All OK	Problems met	Operation
	Replace the diesel pressure regulator Op. 1060E50and check that the fault is no longer present	End of diagnosis	Fault persists	Continue to Step 7
7	CHECK ON CORRECT OPERATION	All OK	Problems met	Operation
	Replace the pressure pump Op. 1060E10and check that the fault is no longer present	End of diagnosis	Fault persists	Continue to Step 8
8	CHECK ON CYLINDER COMPRESSION	All OK	Problems met	Operation
	Carry out the cylinder compression test Op. 0520G15	Continue to Step 10	Cylinder compression insufficient	Continue to Step 9
9	CHECKING CAUSE OF INSUFFICIENT COMPRESSION	All OK	Problems met	Operation
	Carry out R.R. on head to check the valve seal and check the condition of the cylinders/piston rings	Continue to Step 9	Insufficient valve seal	Overhaul the cylinder head
10	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 engine management control unit Op. 1060G80

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Parts & tools for this job For 2003 Fiat Idea

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