23 · Diagnostics

Engine starts with difficulty

Make: Alfa Romeo
Model: 159 Factory Service Manual
Year: 2005–2011
Section: Starting › Engine starts with difficulty

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Fault diagnosisEngine starts with difficulty

ENGINE STARTS WITH DIFFICULTY

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

The engine, especially when cold, starts with difficulty only after repeated attempts. When the key is turned, the instruments light up as normal, the starter motor turns, but the engine has difficulty in starting.

0	PRELIMINARY CHECKS	All OK	Problems met	Operation
		Results of the tests
	Check, in order: that there are no obstructions in the air filter; the condition of the air intake circuit seal of the diesel pipes; that there is no petrol, water, paraffin or dirt in the diesel filter. the correct operation of the exhaust pipes.	Continue to Step 1	Air intake circuit component	Repair or replace the defective component
			Filter blocked	Replace the air filter Op. 1048A10
			Filter blocked	Replace the diesel filter cartridge Op. 1044B20
			Leaks from the diesel pipes	Retighten the pipes, and if necessary replace them.
			Presence of water, petrol, paraffin or dirt detected	Clean the tank and pipes and replace the diesel filter cartridge Op. 1044B20
			Obstruction in the exhaust system	Replace the damaged system component
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	An error is detected in the control unit	Continue following the instructions for the diagnostic equipment
		Continue to Step 2	Unreliable parameters	Continue following the instructions for the diagnostic equipment
2	HIGH PRESSURE CHECK	All OK	Problems met	Operation
	Connect the diagnostic equipment to the diagnostic socket. Check as described in the test See Test 1060D Check high pressure fuel circuit that the diesel pressure parameter is correct	Continue to Step 10	Pressure not correct	Continue to Step 3
3	CHECK ON RETURN LOW PRESSURE	All OK	Problems met	Operation
	Check as described in the test See Test 1060A Low return fuel pressure circuit check that the pressure in the return pipe to the tank is under 1 bar	Continue to Step 4	Pressure above maximum limit: return pipe to tank blocked	Repair the pipe; if necessary replace it
4	LOW SUPPLY PRESSURE CHECK	All OK	Problems met	Operation
	Check as described in the test See Test 1060B Low fuel pressure supply circuit check that the diesel pressure between the filter and pressure pump is between 2 and 3 bar	Continue to Step 10	Pressure below minimum limit or above maximum limit	Continue to Step 5
5	LOW SUPPLY PRESSURE CHECK	All OK	Problems met	Operation
	Close the return pipe downstream of the low pressure regulator valve, located in the fuel filter cover, using the special tool and carry out the test See Test 1060B Low fuel pressure supply circuit check again with the pipe closed, checking that the filter outlet pressure remains below 2 bar	Continue to Step 6	Pressure rises to 5 bar: blocked pressure regulation valve on filter support	Replace the diesel filter cover Op. 1044B16
6	LOW SUPPLY PRESSURE CHECK	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 7	Difference in pressure greater than 1 bar	Replace the diesel filter cartridge Op. 1044B20
7	LOW SUPPLY PRESSURE CHECK	All OK	Problems met	Operation
	Check that the supply pump pressure at the filter inlet is over 2.2 bar	Continue to Step 10	Pressure below 2 bar	Continue to Step 8
8	LOW SUPPLY PRESSUR CHECK	All OK	Problems met	Operation
	Measure the difference in pressure between electric pump outlet and filter inlet, checking that it is less than 0.3 bar	Continue to Step 9	Difference in pressure greater than 0.3 bar	Replace the pipe
9	LOW SUPPLY PRESSURE CHECK	All OK	Problems met	Operation
	Check as described in the test See Test 1040AA Check supply voltage and absorption current that the pump''s supply voltage is 12V and that the absorbed current is between 2 and 10 amps.	Continue to Step 10	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. 1040A70 and clean the fuel tank
10	CORRECT OPERATION CHECK	All OK	Problems met	Operation
	Replace the DRV high-pressure regulator and check that the fault is no longer present	End of diagnosis	Fault persists	Continue to Step 11
11	CORRECT OPERATION CHECK	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 12
12	CHECK ON CYLINDER COMPRESSION	All OK	Problems met	Operation
	Carry out the cylinder compression test	Continue to Step 13	Cylinder compression insufficient	Continue to Step 13
13	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 14	Insufficient valve seal	Overhaul the cylinder head Op. 1016E10
		Continue to Step 14	Cylinders/piston rings worn	Repair the leak
14	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 Search for the fault starting from another symptom''

1.8, 1.9 JTS, 2.2 JTS, 3.2 JTS

0	PRELIMINARY CHECKS	All OK	Problems encountered	Operation
		Test results
	Before start-up, check that the MIL warning light is on and goes off when the engine has started. Also check that after-market accessories have not been fitted	Move on to Step 1	The MIL warning light 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 stays on with the engine started	Continue as instructed in the See table K101 MIL WARNING LIGHT STAYS ON (ENGINE STARTS)
			After-market accessories present	Check that these accessories have been correctly installed
1	CONTROL UNIT ELECTRICAL CONNECTION CHECK	All OK	Problems encountered	Operation
	Check that the engine control unit electrical connections are correct See E5030 PETROL ENGINES ELECTRONIC MANAGEMENT In particular, check that: - the earth has been correctly connected - resistances between control units See M010 ENGINE MANAGEMENT ECU and the battery negative See A001 BATTERY is less than 0.5 Ohm	Move on to Step 2	Earth connections incorrect	Restore the correct connections
		Move on to Step 2	Resistance to battery negative greater than 0.5 Ohms	Restore the correct connections
2	CHECK CONTROL UNIT FASTENING	All OK	Problems encountered	Operation
	Check that the control unti is correctly fastened in its seat Op. 1056F82 CONTROL UNIT SINGLE OF INJECTION IGNITION SYSTEM R R	Move on to Step 3	Fastening of control unit incorrect	Renew the correct fastening of the control unit Op. 1056F82 CONTROL UNIT SINGLE OF INJECTION IGNITION SYSTEM R R
3	TEMPERATURE SENSOR CHECK	All OK	Problems encountered	Operation
	Check that the engine coolant temperature sensor is not blocked, check the engine coolant and intake air temperature readings on the diagnostic instrument, check that the difference between both values is not greater than 3° C.	Move on to Step 4	Temperature values out of range	Check the coolant temperature sensor is operating correctly See Test 1056BC ENGINE COOLANT TEMPERATURE SENSOR OPERATION CHECK
4	RPM SENSOR CHECK	All OK	Problems encountered	Operation
	Check that the rpm sensor resistance reading is between 700 and 1200 Ohms in all temperature ranges	Move on to Step 5	Reistance values out of range	Change the rpm sensor Op. 5510C26 ENGINE RPM SENSOR - R+R
5	FUEL PUMP RELAY CHECK	All OK	Problems encountered	Operation
	Insert the ignition key and check the pump comes on for 2 seconds	Move on to Step 6	The pump is not activated	Check that the fuel pump relay is working properly See Test 1040AD FUEL PUMP RELAY CHECK
6	POWER SUPPLY 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	Move on to Step 7	Faults present	The test indicates the solution
7	INJECTOR CHECK	All OK	Problems encountered	Operation
	Check that the injectors are not stuck closed or imperfectly closed by conducting See Test 1056BA INJECTOR OPERATION CHECK	Move on to Step 8	Faults present	The test indicates the solution
8	CHECK FOR IMPURITIES IN THE FUEL	All OK	Problems encountered	Operation
	Check that the fuel does not contain impurities such as water, alcohol or suspended particles by performing test See T FUEL QUALITY CHECK	Move on to Step 9	Faults present	The test indicates the solution
9	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 signs of corrosion or moisture. Also check that the ignition coils are operating correctly by conducting See Test 5510CC IGNITION COIL CHECK	Move on to Step 10	One of the coils is operating incorrectly	Refit the coil correctly Op. 5510C14 IGNITION COIL/S - R.R.
			One of the coils shows signs of corrosion/moisture	Replace the coil Op. 5510C14 IGNITION COIL/S - R.R.
			One of the coils is operating incorrectly	The test indicates the solution
10	SPARK PLUG CHECK	All OK	Problems encountered	Operation
	Remove the spark plugs. Op. 5510D10 SPARK PLUGS - R+R and check that they do not display signs of faults as indicated in the test See T SPARK PLUG STATE CHECK	Move on to Step 11	Faults present	The test indicates the solution
11	CYLINDER COMPRESSION CHECK	All OK	Problems encountered	Operation
	Carry out the cylinder compression check Op. 0510A10 CYLINDER COMPRESSION - CHECK FOR LOOSE SPARK PLUGS OR INJECTORS	Move on to Step 13	Cylinder compression insufficient	Move on to Step 12
12	CHECK ON CAUSE OF INSUFFICIENT COMPRESSION	All OK	Problems encountered	Operation
	R/R head for valve leakage test Check condition of cylinders/piston rings	Move on to Step 13	Valve seal insufficient	Overhaul the head Op. 1016E10 SINGLE CYLINDER HEAD, REMOVED - OVERHAUL
			Cylinders/piston rings worn	Restore the seal
			Cylinder head/cylinder block-crankcase matching faulty	Restore correct matching
13	TIMING CHECK	All OK	Problems encountered	Operation
	Check that the valve gear timing is correct Op. 0510A20 TIMING GEAR WITH BELT DRIVE - CHECK - CARRY OUT OPERATION WITH CAM COVER(S) REMOVED AND TAPPETS ADJUSTED AND CRANKSHAFT PULLEY DETACHED (IF NECESSARY)	Move on to Step 14	Valve gear timing not correct	Restore the correct valve gear timing
14	CHECK ON CORRECT OPERATION	All OK	Problems encountered	Operation
	Check the fault has disappeared	End of diagnosis	The fault persists	Contact technical service for further information on the problem

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Parts & tools for this job For 2005 Alfa Romeo 159

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