Engine not running smoothly / (irregular operation)

Make: Alfa Romeo
Model: 159 Factory Service Manual
Year: 2005–2011
Section: Engine › Engine not running smoothly / (irregular operation)

‹ Prev Engine not running smoothly / (losing power)Next › Engine not running smoothly

Fault diagnosisEngine not running smoothly / (irregular operation)

ENGINE NOT RUNNING SMOOTHLY / (IRREGULAR OPERATION)

1.9 JTD 8V, 1.9 JTD 16V, 2.4 JTD 20V

During driving, the engine misses and loses performance

0	PRELIMINARY CHECKS	All OK	Problems met	Operation
		Results of the tests
	Preliminarily check: battery earth correctly fixed See E1010 SUPPLY condition of the air intake circuit the condition of the spark plugs quality of the fuel check engine wiring earths	Continue to Step 1	Earth fastening not correct	Restore correct fixing
			Air intake circuit fault	Restore the correct operation of the intake circuit
			Spark plugs not the type recommended by the manufacturer	Replace the spark plugs
			Impurities in the fuel	Clean the fuel tank
			Earths faulty	Restore correct fixing
1	CHECKING 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 all the parameters	Continue to Step 2	Error detected	Continue following the instructions for the diagnostic equipment
		Continue to Step 2	Inconsistent parameter	Anaylze the factors that have caused this inconsistency
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; the plausibility of the parameters, in particular: rail pressure - rail pressure setting, injection times, revs (graphic acquisition of signal), engine temperature	Continue to Step 3	Error detected	Continue following the instructions for the diagnostic equipment
		Continue to Step 3	Inconsistent parameter	Anaylze the factors that have caused this inconsistency
3	LOW PRESSURE CIRCUIT CHECK	All OK	Problems met	Operation
	Check that the fuel pressure is correct	Continue to Step 4	Incorrect pressure: obstructions in the 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: petrol pump damaged or not correctly supplied	Replace fuel pump assembly Op. 1040A70
4	RAIL PRESSURE SENSOR CHECK	All OK	Problems met	Operation
	Check the operation of the rail sensor	Continue to Step 5	Pressure sensor faulty	Replace sensor.
5	PRESSURE REGULATOR CHECK	All OK	Problems met	Operation
	Check that the voltage regulator is working	Continue to Step 6	Pressure regulator faulty	Replace the pressure regulator
6	HIGH PRESSURE PUMP CHECK	All OK	Problems met	Operation
	Check the operation of the high pressure pump	Continue to Step 7	High pressure pump faulty	Replace high pressure pump
7	CHECK ON INJECTORS	All OK	Problems met	Operation
	Check the continuity/insulation of the injector wiring; in particular, make sure that the injector operating signal is present See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT	Continue to Step 8	No signal, wiring broken	Renew the wiring See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT
		Continue to Step 8	No signal, wiring not broken	Replace engine management control unit

1.9 JTS, 2.2 JTS, 3.2 JTS

There are variations in the engine power with the accelerator pedal position stable or the cruise control on. It seems that the vehicle is accelerating or slowing down without the position of the accelerator pedal changing.

Make sure that these fluctuations do not take place at the same time as the air conditioning compressor is switching on or off. Both events could be noticed by an inexperienced driver and perceived as sudden engine acceleration or failure.

0	PRELIMINARY CHECKS	All OK	Problems encountered	Operation
		Test results
	Before starting, check that the MIL warning light is on and that it goes off once the engine has been started. Also check that no accessories have been fitted in the after-market	Move on to Step 1	The MIL warning lights does not come on when the key is inserted	Continue as instructed in the See table K100 MIL WARNING LIGHT NOT WORKING (REMAINS OFF BEFORE STARTING)
			The MIL warning light remains on with the engine started	Continue as instructed in the See table K101 MIL WARNING LIGHT STAYS ON (ENGINE STARTS)
			There are accessories that have been fitted in the after-market	Check that these accessories have been fitted correctly
1	CONTROL UNIT ELECTRICAL CONNECTIONS CHECK	All OK	Problems encountered	Operation
	Check that the electrical connections for the engine management control unit are correct See E5030 PETROL ENGINES ELECTRONIC MANAGEMENT In particular, check that: - the earth is correctly connected - the resistance between the control unit See M010 ENGINE MANAGEMENT ECU and the battery negative See A001 BATTERY is less than 0.5 Ohm	Move on to Step 2	Connection to earth incorrect	Restore the correct connections
		Move on to Step 2	Resistance to battery negative more than 0.5 Ohm	Restore the correct connections
2	CONTROL UNIT FASTENING CHECK	All OK	Problems encountered	Operation
	Check that the control unit is correctly fastened in its housing Op. 1056F82 CONTROL UNIT SINGLE OF INJECTION IGNITION SYSTEM R R		Control unit fastening incorrect	Renew the correct fastening of the control unit Op. 1056F82 CONTROL UNIT SINGLE OF INJECTION IGNITION SYSTEM R R
3	FUEL FEED CIRCUIT CHECK	All OK	Problems encountered	Operation
	Check there are no faults in the fuel supply circuit by performing the See Test 1040OA FUEL SUPPLY CIRCUIT CHECK		Faults present	The operation to solve the problem is described in the actual test
4	CHECK FOR THE PRESENCE OF IMPURITIES IN THE FUEL	All OK	Problems encountered	Operation
	Check that there are no impurities such as water, alcohol or particles in suspension in the fuel by carrying out the See T FUEL QUALITY CHECK	Move on to Step 5	Faults present	The operation to solve the problem is described in the actual test
5	INJECTOR CHECK	All OK	Problems encountered	Operation
	Check that the injectors are not stuck shut or not perfectly closed by carrying out the See Test 1056BA INJECTOR OPERATION CHECK	Move on to Step 6	Faults present	The operation to solve the problem is described in the actual test
6	IGNITION COIL CHECK	All OK	Problems encountered	Operation
	Check that the ignition coils are correctly fitted in their seats. Also check that they do not show any signs of corrosion or dampness. Lastly, check that the ignition coils are working properly, by carrying out the See Test 5510CC IGNITION COIL CHECK	Move on to Step 7	One of the coils is not fitted correctly	Refit the coil correctly Op. 5510C14 IGNITION COIL/S - R.R.
			One of the coils shows signs of corrosion/dampness	Replace the coil Op. 5510C14 IGNITION COIL/S - R.R.
			One of the coils is not working properly	The operation to solve the problem is described in the actual test
7	SPARK PLUGS CHECK	All OK	Problems encountered	Operation
	Remove the spark plugs Op. 5510D10 SPARK PLUGS - R+R and check that they are no signs of faults, following the instructions in the See T SPARK PLUG STATE CHECK	Move on to Step 8	Faults present	The operation to solve the problem is described in the actual test
8	RPM SENSOR CHECK	All OK	Problems encountered	Operation
	Check that the resistance value of the rpm sensor in all temperature ranges is between 700 and 1200 Ohm	Move on to Step 9	Resistance values outside of the range	Change the rpm sensor Op. 5510C26 ENGINE RPM SENSOR - R+R
9	EXHAUST SYSTEM CHECK	All OK	Problems encountered	Operation
	Check that the exhaust circuit is not leaking, there are no loose connections, constrictions, deformations or damage	Move on to Step 10	Faults present	Restore the correct fastening of the problem components. Replace them if necessary
10	PHASE TRANSFORMER ERRORS CHECK	All OK	Problems encountered	Operation
	Connect the diagnostic equipment and check that none of the following errors is present: P0011, P0014	Move on to Step 11	One or more of the errors indicated is present	Continue as described by the diagnostic equipment
11	CHECK ON CORRECT OPERATION	All OK	Problems encountered	Operation
	Check the fault has disappeared	End of diagnosis	The fault persists	Contact the Technical Expert for further information on the problem

‹ Prev Engine not running smoothly / (losing power)Next › Engine not running smoothly

Parts & tools for this job Staging For 2005 Alfa Romeo 159

Links open Amazon search results in a new tab. As an Amazon Associate I earn from qualifying purchases.