Engine does not produce best performance

Make: Fiat
Model: Idea Factory Service Manual
Year: 2003–2012
Section: Engine › Engine does not produce best performance

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Fault diagnosisEngine does not produce best performance

ENGINE DOES NOT PRODUCE BEST PERFORMANCE

1.4 16v

0	PRELIMINARY CHECKS	All OK	Problems met	Operation
		Results of the tests
	Preliminarily check: the condition of air filter the condition of the air intake circuit; no obstructions in the exhaust pipe	Continue to Step 1	Air intake circuit fault	Eliminate the problem, if necessary replacing the filter element Op. 1048A14
		Continue to Step 1	Pipe obstructed	Restore the operation of the exhaust pipe
1	CHECKING 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	ROAD TEST WITH DIAGNOSTIC EQUIPMENT	All OK	Problems met	Operation
	Carry out a road test 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
			Sudden occurrence of another error detected	Continue following the instructions for the diagnostic equipment
			Parameters inconsistent	Continue following the instructions for the diagnostic equipment
3	FUEL PRESSURE ROAD TEST	All OK	Problems met	Operation
	Road test the vehicle and check the fuel supply pressure Op. 0510C10in the conditions that lead to the anomaly	Continue to Step 4	Insufficient fuel pressure: pipes obstructed	Remove restrictions
		Continue to Step 4	Low fuel pressure: defective pump	Replace the pump assembly Op. 1040A70
4	CHECK ON TIMING	All OK	Problems met	Operation
	Check that the timing is correct Op. 0510A20	Continue to Step 5	Timing not correct	Restore the correct timing
5	CHECK ON CYLINDER COMPRESSION	All OK	Problems met	Operation
	Carry out the cylinder compression test Op. 0510A10	Continue to Step 7	Cylinder compression insufficient	Continue to Step 6
6	CHECK ON CAUSE OF INSUFFICIENT COMPRESSION	All OK	Problems met	Operation
	Carry out R/R on head to check the valve seal Check the condition of the cylinders/piston rings	Continue to Step 7	Insufficient valve seal	Overhaul the cylinder head
		Continue to Step 7	Cylinders/piston rings worn	Repair the leak
7	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

0	PRELIMINARY CHECKS	All OK	Problems met	Operation
		Results of the tests
	Check, in order: the condition of the air intake circuit no faults in the air filter; seal of the diesel pipes; accelerator pedal travel; absence of obstructions in the catalytic converter	Continue to Step 1	Fault in air intake circuit	Repair the air intake circuit
			Air filter blocked	Replace the filter element Op. 1048A14
			Leaks from the diesel pipes	stop the leak
			Accelerator pedal travel incomplete	Eliminate the cause of the problem
			Catalyzer obstructed	Replace the catalyzer Op. 1080B62
			Operation incorrect	Continue to Step 1
1	CHECK TURBOCHARGER ADJUSTMENT	All OK	Problems met	Operation
	With the diagnostic equipment, carry out active diagnosis on the turbocharger regulating solenoid Check the operation of the variable geometry control actuator by carrying out the test See Test 1064BC Variable geometry turbocharger actuator leakage test	Continue to Step 2	Solenoid not working	Check the continuity of the wiring See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENTand if necessary replace the solenoid Op. 1064B34
		Continue to Step 2	Actuator does not work correctly	Check the condition of the vacuum circuit and, if necessary, replace the damaged components
2	CHECK WITH DIAGNOSTIC EQUIPMENT	All OK	Problems met	Operation
	Connect the diagnostic equipment (Examiner or other instruments) to the diagnostic socket Check: for errors in the control unit plausibility of parameters; carry out active diagnosis of E.G.R. solenoid	Continue to Step 3	An error is detected in the control unit	Continue following the instructions for the diagnostic equipment
			unreliable parameters	Continue following the instructions for the diagnostic equipment
			E.G.R. solenoid not working	Check wiring continuity See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT
			E.G.R. solenoid not working	Replace the solenoid valve Op. 1080C24
3	ROAD TEST WITH DIAGNOSTIC EQUIPMENT	All OK	Problems met	Operation
	Road test the vehicle keeping the diagnostic instrument connected. Make sure that the conditions in which the problem occurs are reproduced Check: for errors in the control unit plausibility of all the parameters	Continue to Step 4	Errors suddenly occur in the control unit	Continue following the instructions for the diagnostic equipment
			Parameters off scale	Continue following the instructions for the diagnostic equipment
			Lack of dialogue with the control unit	Restore the connection between engine management control unit and diagnostic connector See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT
4	CHECK ON BRAKE PEDAL SWITCH	All OK	Problems met	Operation
	Check that the brake pedal switch is working properly	Continue to Step 5	Brake pedal does not return	Eliminate the cause of the sticking
			Switch stuck in closed position	Replace the switch Op. 1060G38
			Wiring short circuited	Restore the correct connection
5	CHECK ON TURBOCHARGER	All OK	Problems met	Operation
	Check the operation of the turbocharger as described in the Test See Test 1064BA Check turbo presure	Continue to Step 6	Turbocharger faulty	Replace the turbocharger Op. 1064A19
6	HIGH PRESSURE CHECK	All OK	Problems met	Operation
	Connect the diagnostic equipment (Examiner or other instruments) to the diagnostic socket Check as described in the test See Test 1060D Check high pressure fuel circuitthat the diesel pressure parameter is correct	Continue to Step 14	Pressure not correct	Continue to Step 7
7	CHECK ON RETURN LOW PRESSURE	All OK	Problems met	Operation
	Check as described in the test See Test 1060A Low return fuel pressure circuit checkthat the pressure in the return pipe to the tank is under 1 bar	Continue to Step 8	Pressure above maximum limit: return pipe to tank blocked	Repair the pipe, if necessary, replace it.
8	LOW SUPPLY PRESSUR CHECK	All OK	Problems met	Operation
	Check as described in the test See Test 1060B Low fuel pressure supply circuit checkthat the diesel pressure between filter and pressure pump is between 2 and 3 bar	Continue to Step 14	Pressure below minimum limit or above maximum value	Continue to Step 9
9	LOW SUPPLY PRESSURE CHECK	All OK	Problems met	Operation
	Choke the return pipe and repeat the test See Test 1060B Low fuel pressure supply circuit checkwith the pipe choked, checking that the pressure at the filter outlet remains below 2 bar	Continue to Step 10	Pressure rises to 5 bar: blocked pressure regulation valve on filter support	Replace the valve Op. 1044B16
10	CHECK DELIVERY LOW PRESSURE	All OK	Problems met	Operation
	Check that the difference in pressure upstream and downstream of the filter is less than 1 bar	Continue to Step 11	Difference in pressure greater than 1 bar	Replace the fuel filter cartridge Op. 1044B20
11	CHECK ON RETURN LOW PRESSURE	All OK	Problems met	Operation
	Check that the pressure downstream of the supply pump is over 2.2 bar	Continue to Step 14	Pressure below 2 bar	Continue to Step 12
12	LOW SUPPLY PRESSURE CHECK	All OK	Problems met	Operation
	Measure the difference in pressure between the electric pump outlet and filter inlet, checking that it is less than 0.3 bar	Continue to Step 13	Difference in pressure greater than 0.3 bar	Replace the pipe
13	LOW SUPPLY PRESSURE CHECK	All OK	Problems met	Operation
	Check as described in the test See Test 1060A Low return fuel pressure circuit checkthat the pump's supply voltage is 12V and that the absorbed current is between 2 and 10 amps.	Continue to Step 14	Voltage < 12 V	Check electric wiring See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT
			Current > 10 Amp: pump defective	Replace the fuel pump assembly Op. 1040A70
			Current < 2 Amp.: pump blocked	Replace the fuel pump assembly Op. 1040A70and clean the fuel tank
14	CHECK ON CORRECT OPERATION	All OK	Problems met	Operation
	Replace the DRV pressure regulating valve and check that the fault is no longer present	End of diagnosis	Fault persists	Continue to Step 15
15	CHECK ON CORRECT OPERATION	All OK	Problems met	Operation
	Replace the pressure pump and check that the fault is no longer present	End of diagnosis	Fault persists	Continue to Step 16
16	CHECK ON TIMING	All OK	Problems met	Operation
	Check that the timing is correct Op. 0510A20	Continue to Step 17	Timing not correct	Restore the correct timing
17	VALVE CLEARANCE CHECK	All OK	Problems met	Operation
	Check that the valve tappet clearance is correct. Op. 1036H14	Continue to Step 18	Valve clearance not correct	Adjust the tappets Op. 1036H10
18	CHECK ON CYLINDER COMPRESSION	All OK	Problems met	Operation
	Carry out the cylinder compression test Op. 0520G15	Continue to Step 20	Cylinder compression insufficient	Continue to Step 19
19	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 20	Insufficient valve seal	Overhaul the cylinder head
20	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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