23 · Diagnostics

Engine not running smoothly

Make: Alfa Romeo
Model: 159 Factory Service Manual
Year: 2005–2011
Section: Engine › Engine not running smoothly

‹ Prev Engine not running smoothly / (irregular operation)Next › Engine does not produce best performance

Fault diagnosisEngine not running smoothly

ENGINE NOT RUNNING SMOOTHLY

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

There are decreases in performance during acceleration

0	PRELIMINARY CHECKS	All OK	Problems met	Operation
		Results of the tests
	Check, in order: the condition of the air intake circuit that there are no faults in the air filter whether the diesel pipes are leaking the accelerator pedal travel that there is no water, petrol, paraffin or dirt in the fuel tank and filter that there no obstructions in the exhaust system	Continue to Step 1	Fault in air intake circuit	Repair the air intake circuit
			Air filter blocked	Replace the filter element
			Leak from diesel pipes	Eliminate the leaks
			Accelerator pedal travel incomplete	Eliminate the cause of the problem
			Presence of water, petrol, paraffin or dirt detected	Clean the tank and pipes and replace the filter element
			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	CHECK EGR AND ADJUST TURBOCHARGER	All OK	Problems met	Operation
	Connect the diagnostic equipment (Examiner or other instruments) to the diagnostic socket. Carry out active diagnosis of EGR solenoid valve Carry out active diagnosis of the turbocharger regulator solenoid valve Check operation of the variable geometry control actuator See Test 1064BC Variable geometry turbocharger actuator leakage test	Continue to Step 3	EGR solenoid valve not working	Check the continuity of the wiring See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT , if necessary, replae the solenoid valve Op. 1080C74
			Turbocharger solenoid valve not working	Check the continuity of the wiring See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT , if necessary, replae the solenoid valve Op. 1064A28
			Actuator does not work correctly	Check the condition of the vacuum circuit and, if necessary, replace the damaged components
3	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: for errors in the control unit plausibility of all the parameters	Continue to Step 4	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
			Lack of dialogue with the control unit	Restore the connection between the engine management control unit and the diagnostic connector.
4	CHECK ON TURBOCHARGER	All OK	Problems met	Operation
	Check the operation of the turbocharger as described in the Test See Test 1064BA Check the supercharging pressure	Continue to Step 5	Turbocharger faulty	Replace the turbocharger unit
5	CHECK ON CORRECT OPERATION	All OK	Problems met	Operation
	Check that the fault is no longer present		Fault persists: control unit faulty	Replace control unit Op. 1060G80 Search for the fault starting from another symptom''

‹ Prev Engine not running smoothly / (irregular operation)Next › Engine does not produce best performance

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.