D10 ENGINE IDLE IRREGULAR - Lancia - MUSA - eLearn

184000417 - D10 ENGINE IDLE IRREGULAR

The engine is not running smoothly when idling; in particular, it does not maintain a constant, regular value as the load varies (e.g. when electrical devices are switched on)

0	PRELIMINARY CHECKS	All OK	Problems met	Operation
		Results of the tests
	Check: the condition of the air intake circuit condition and correct operation of the air filter	Continue to Step 1	Fault in air intake circuit	Repair the air intake circuit
		Continue to Step 1	Air filter blocked	Replace the filter element Op. 1048A14
1	CHECK 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 errors in the control unit plausibility of all the parameters carry out active diagnosis of E.G.R. solenoid	Continue to Step 2	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 engine management control unit and diagnostic connector See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT
			Solenoid not working	Check the continuity of the wiring See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT and if necessary replace the solenoid Op. 1080C74
2	CHECK ON FUEL FILTER	All OK	Problems met	Operation
	Check the operation of the fuel filter	Continue to Step 3	Presence of water, petrol, paraffin or dirt detected	Clean the tank and pipes and replace the diesel filter cartridge Op. 1044B20
3	CHECK ON CYLINDER COMPRESSION	All OK	Problems met	Operation
	Carry out the cylinder compression test	Continue to Step 5	Cylinder compression insufficient	Continue to Step 4
4	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 5	Insufficient valve seal	Overhaul the cylinder head Op. 1016E10
5	PRESSURE SENSOR CHECK	All OK	Problems met	Operation
	Check that the sensor is working properly: after the engine has reached operating temperature, make sure that, with the engine IDLING and pressure regulator duty cycle operation between 16 and 20%, the minimum pressure measured by the sensor is around 300 bar +/-5%	Continue to Step 8	Pressure sensor faulty	Replace the pressure sensor
6	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 14	Pressure too high	Continue to Step 5
		Continue to Step 14	Pressure too low	Replace the pressure regulator Op. 1060E50 then continueContinue to Step 5
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 check that 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 PRESSURE CHECK	All OK	Problems met	Operation
	Check as described in the 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 14	Pressure below minimum limit or above maximum limit	Continue to Step 9
9	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 10	Pressure rises to 5 bar: blocked pressure regulation valve on filter support	Replace the diesel filter cover
10	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 11	Difference in pressure greater than 1 bar	Replace the diesel filter cartridge
11	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 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 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 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 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. 1040A70 and clean the fuel tank
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