22 · Diagnostics

Misfire error

Make: Alfa Romeo
Model: GT Factory Service Manual
Year: 2003–2010
Section: Examiner › Misfire error

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Fault diagnosisMisfire error

MISFIRE ERROR

1.8 T.SPARK, 3.2 V6

The diagnostic equipment signals the following error: Misfire

0	PRELIMINARY CHECKS	All OK	Problems met	Operation
		Results of the tests
	Visually check on the instrument panel that the MIL warning light is not flashing while the car is driving	Continue to Step 1	I.E. fault warning light flashing	Continue according to the instructions in See table See table K48 I.E. FAILURE WARNING LIGHT FLASHING
1	ERROR CHECK	All OK	Problems met	Operation
	Connect the diagnostic equipment (Examiner or Examiner Plus) and record the errors and environmental parameters. Check for ''(General) Misfire'' error only	End of diagnosis	Upstream Lambda sensor signal error present	Continue according to the instructions in See table See table Z56 UPSTREAM LAMBDA SENSOR SIGNAL ERROR
			Mixture strength error present	Continue according to the instructions in See table See table Z50 MIXTURE STRENGTH ERROR
			Cylinder X misfire error present	Continue according to the instructions in See table See table Z54 MISFIRE ERROR IN ONE CYLINDER
			General misfire error, catalyzer and/or downstream Lambda sensor signal errors only present	Continue to Step 2
			Other errors are present	Identify and eliminate the cause of the problem. Continue to Step 11
2	CONTROL UNIT CIRCUIT CHECK	All OK	Problems met	Operation
	Visually inspect the condition of the engine management control unit wiring, connections and earth. There should be no faults	Continue to Step 3	Faults in the control unit electrical circuit	Restore the correct connections See See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT . If necessary, replace the components involved. Continue to Step 11
3	CHECK ON FUEL PRESSURE	All OK	Problems met	Operation
	Check that the fuel system pressure is correct Op. Op. 0510C10 FUEL SYSTEM - CHECK DELIVERY PRESSURE	Continue to Step 4	Pressure not correct	Restore the correct pressure; if necessary, replace the faulty components. Continue to Step 11
4	FUEL QUALITY CHECK	All OK	Problems met	Operation
	Check the quality of the fuel, making sure that there is no water or other impurities	Continue to Step 5	Impurities present	Clean the tank Op. 1040A24 and introduce new fuel. Continue to Step 11
5	SIGNAL PLAUSIBILITY CHECK	All OK	Problems met	Operation
	Checking plausibility of the MAP/debimeter sensor signal by carrying out the	Continue to Step 6	The signal is not plausible	Replace the flow meter Op. 1056B09 Continue to Step 12
6	INTAKE AND EXHAUST SYSTEM LEAKAGE CHECK	All OK	Problems met	Operation
	Check the exhaust system visually and by listening. In particular, check that there are no leaks downstream of the MAP/flow meter sensor, also taking into consideration: Blow-by; Canister circuit; Brake servo vacuum pipes; Injector O-Rings	Continue to Step 7	There are leaks	Restore the correct seal for the exhaust system, if necessary, replace the components involved. Continue to Step 11
7	Check that there are no problems with the engine. In particular, check:	All OK	Problems met	Operation
	Cylinder compression correct Op. Op. 0510A10 CYLINDER COMPRESSION - CHECK FOR LOOSE SPARK PLUGS OR INJECTORS ; Correct engine timing Op. Op. 0510A20 TIMING GEAR WITH BELT DRIVE - CHECK - CARRY OUT OPERATION WITH CAM COVER(S) REMOVED AND TAPPETS ADJUSTED ; Correct rpm sensor position; Gap between rpm sensor and flywheel within permissible limits; No visible faults on the flywheel, such as broken or chipped teeth	Continue to Step 8	Engine timing incorrect	Ensure engine timing is correct Op. 1032B14 Continue to Step 11
			Rpm sensor incorrectly positioned	Reposition the sensor correctly. Continue to Step 11
			Flywheel defective	Replace the phonic wheel Op. Op. 1024B60 PHONIC WHEEL ON FLYWHEEL - R R Continue to Step 11
			Compression insufficient	Continue to Step 8
8	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 9	Insufficient valve seal	Overhaul the cylinder heads Op. Op. 1016E26 CYLINDER HEADS - OVERHAUL Continue to Step 11
		Continue to Step 9	Cylinders/piston rings worn	Renew the seal. Continue to Step 11
9	KINEMATIC MECHANISM CHECKS	All OK	Problems met	Operation
	Check that the kinematic mechanism is not oscillating by road testing the vehicle. In particular: Clutch not jerking; Couplings/bearings not faulty; Engine mountings and supports not faulty; Suspension loading correct; Wheel balancing correct	Continue to Step 10	Clutch jerking	Replace the clutch Op. Op. 1810A20 CLUTCH - R + R Continue to Step 11
			Couplings, bearings, mountings or supports faulty	Replace the components involved. Continue to Step 11
			Front suspension not loaded	Replace the shock absorber Op. Op. 4410A12 FRONT SUSPENSION DAMPER (ONE), LH OR RH - FOR MCPHERSON STRUT SYSTEM - INCLUDES DISMANTLING/RE-BUILDING OF ASSEMBLY AT BENCH R R Continue to Step 11
			Wheels not balanced	Balance the wheels. Replace the faulty tyres if necessary Continue to Step 11
10	INDIVIDUAL CYLINDER ERROR CHECK	All OK	Problems met	Operation
	Connect the diagnostic equipment (Examiner or Examiner Plus) Check for the presence of Misfire at cylinder X error	End of diagnosis	Error present in at least 1 cylinder	Continue according to the instructions in See table See table Z54 MISFIRE ERROR IN ONE CYLINDER
		End of diagnosis	Error not present at a specific cylinder	Continue according to the instructions in See table See table Z54 MISFIRE ERROR IN ONE CYLINDER
11	ERROR CANCELLING AND CHECKING	All OK	Problems met	Operation
	Use a tester to cancel the errors in the control unit. Carry out a road test and ensure the error does not recur.	Continue to Step 12	The fault persists
12	CHECK ON CORRECT OPERATION	All OK	Problems met	Operation
	Check that the fault is no longer present	End of diagnosis

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Parts & tools for this job For 2003 Alfa Romeo GT

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