Engine not running smoothly / (irregular operation)

Make: Fiat
Model: Ducato Factory Service Manual
Year: 2002–2006
Section: Engine › Engine not running smoothly / (irregular operation)

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Fault diagnosisEngine not running smoothly / (irregular operation)

ENGINE NOT RUNNING SMOOTHLY / (IRREGULAR OPERATION)

Engine judders when car is in motion and is not efficient.

STEP	OPERATIONS TO BE CARRIED OUT	TEST RESULTS
0	PRELIMINARY CHECKS	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the following, in order: condition of the air intake circuit; that there are no faults in the air filter; the seal of the diesel pipes; no obstructions in the catalytic converter; no water, petrol, paraffin or dirt in the fuel tank and filter; battery earth terminal fastening.	Move on to Step 1	Air intake circuit faulty	Repair the air intake circuit
			Air filter blocked	Replace the filter element Op. 1048A14 AIR CLEANER FILTERING ELEMENT - REPLACE.
			Leaks from diesel pipes	Eliminate the leaks
			Water, petrol, paraffin or dirt found to be present	Clean the tank and pipes and replace the filter element Op. 1080B62 CATALYTIC CONVERTER - R + R Op. 1044B20 FUEL FILTER FILTERING ELEMENT - REPLACE
			Catalytic converter obstructed	Replace the catalytic converter Op. 1080B62 CATALYTIC CONVERTER - R + R
			Battery earth terminal insecure	Secure battery earth terminal See E5010 STARTING AND RECHARING
1	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Connect the tester to the tester output. Check: that there are no errors in the control unit; the plausibility of the parameters; correct injector operation	Move on to Step 2	Error detected in the control unit	Continue following the instructions for the diagnostic equipment
			Parameters not plausible	Continue following the instructions for the diagnostic equipment
			No communication with the control unit	Restore the connection between the engine management control unit and the diagnostic connector See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT
			Injectors defective	Replace the injectors Op. 1060F10 FUEL INJECTORS
2	ROAD TEST USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Carry out a road test reproducing the conditions in which the fault occurs, keeping the diagnostic equipment connected. Check: that there are no errors in the control unit; parameter plausibility.	Move on to Step 3	Error detected in the control unit	Continue following the instructions for the diagnostic equipment
			Parameters not plausible	Continue following the instructions for the diagnostic equipment
			No communication with the control unit	Restore the connection between the engine management control unit and the diagnostic connector See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT
3	CHECK ON CORRECT OPERATION	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check that the fault is no longer present	End of diagnosis	Fault persists	Replace the engine management control unit Op. 1060G80 DS ELECTRIC INJECTION CONTROL UNIT - R R

2.0 16V · BIPOWER

Engine judders when car is in motion and is not efficient.

STEP	OPERATIONS TO BE CARRIED OUT	TEST RESULTS
0	PRELIMINARY CHECKS	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check: the leads are properly fastened to the battery wiring on engine correctly fastened to earth	Move on to Step 1	Battery lead fastening incorrect	Restore correct lead fastenings
		Move on to Step 1	Wiring leads incorrectly fastened to engine	Restore the correct connection
1	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Connect the Examiner tester to the tester output and check the following on the methane engine management control unit Check, in error mode: for faults in the methane control unit	Move on to Step 2	Error detected in the control unit	Continue following the instructions for the diagnostic equipment
2	CHECK METHANE PRESSURE	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	With the tester connected to the tester output, check on engine management control unit to ensure methane pressure parameter is correct See Test 1044E GAS PRESSURE CONTROL DEVICE See Test 1058AA See Test 1058A GAS CIRCUIT MULTI POINT INJECTION	Move on to Step 3	Pressure regulator defective	Replace the pressure regulator Op. 1044C10 FUEL PRESSURE REGULATOR - R + R
		Move on to Step 3	Methane pressure sensor defective	Replace pressure sensor Op. 1058A44 CNG/FUEL SWITCH - R R
3	CHECK METHANE INJECTOR SEAL	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check methane injector seal is efficient as described in Test 1058OB See Test 1058O CNG SUPPLY TESTS	Move on to Step 4	Significant leak from a methane injector	Replace the injector Op. 1058A70 INJECTOR(1) OF CNG INJECTION SYSTEM - R RWITH CNG MANIFOLD PIPE REMOVED INCLUDES GASKET REPLACEMENT
		Move on to Step 4	Ineffective seals on high and low pressure connectors	Restore connector seals
4	CHECK METHANEN INJECTORS	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	With the tester connected to the tester output, check the following at the methane engine control unit in active diagnosis mode: correct injector operation. Check injector operation by running Test 1058AB See Test 1058A GAS CIRCUIT MULTI POINT INJECTION	Move on to Step 5	Methane injector fault	Replace the injectors Op. 1058A70 INJECTOR(1) OF CNG INJECTION SYSTEM - R RWITH CNG MANIFOLD PIPE REMOVED INCLUDES GASKET REPLACEMENT
5	CHECK ON CORRECT OPERATION	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check that the fault is no longer present	End of diagnosis	Fault persists	Replace the methane engine management control unit Op. 1058A80 CNG INJECTION UNIT CONTROL UNIT - R R

2.0 16V · GPL

Engine judders when car is in motion and is not efficient.

STEP	OPERATIONS TO BE CARRIED OUT	TEST RESULTS
0	PRELIMINARY CHECKS	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check: the leads are properly fastened to the battery; wiring on engine correctly fastened to earth; correct installation of LPG injector delivery and return pipes; LPG system seal using an electronic leak detector to identify gas leaks; Intake side air leaks downstream of throttle body; leaks from exhaust manifold valve seal/valve clearance by carrying out cylinder compression test; camshaft timing; LPG filters	Move on to Step 1	Battery lead fastening incorrect	Restore correct lead fastenings
			Engine wiring earth fastening	Renew the correct fastening
			Pipes not fitted correctly	Renew the correct fastening
			imperfect system seal	Restore the correct seal
			Absence of intake side air leaks	Restore correct operation
			Leaks from exhaust manifold	Restore correct operation
			Valve seal/clearance incorrect	Restore valve seal/clearance Op. 1036H10 VALVE TAPPETS - CHECK AND ADJUST CLEARANCE
			Timing not correct	Restore correct timing Op. 1032B14 TOOTHED TIMING BELT - R + R FOR TIMING ADJUSTMENT OR REPLACEMENT VERSIONS WITH AIR CONDITIONER
			LPG filters blocked	Replace the filters
1	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Connect the tester to the tester output and check the following on the LPG engine management control unit in error mode: for faults in the LPG control unit;	Move on to Step 2	Error detected in the control unit	Continue following the instructions for the diagnostic equipment
2	LPG INJECTOR CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	With the tester connected to the tester output, check the following at the LPG engine control unit in active diagnosis mode: correct injector operation Check injector operation by running Test 1057BB See Test 1057B GPL MULTIPOINT INJECTION FUEL SYSTEM	Move on to Step 3	LPG injector fault	Replace the injectors
3	LPG INJECTOR SEAL CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check LPG injector operation by running Test 1057BC See Test 1057B GPL MULTIPOINT INJECTION FUEL SYSTEM	Move on to Step 4	Ineffective injector seal	Replace the injectors
4	LPG PRESSURE SENSOR CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the operation of the LPG pressure sensor by running Test 1043BB See Test 1043B GPL FUEL CIRCUIT PIPES	Move on to Step 5	Supply not correct	Restore correct power supply See E5031 LPG FUEL SYSTEM ELECTRONIC MANAGEMENT
			Wiring defective	Restore wiring See E5031 LPG FUEL SYSTEM ELECTRONIC MANAGEMENT
			LPG pressure sensor defective	Replace pressure sensor
5	CHECK LPG PRESSURE	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	With the tester connected to the tester output, check on LPG engine management control unit to ensure gas pressure parameter is correct by running Test 1057BA See Test 1057B GPL MULTIPOINT INJECTION FUEL SYSTEM	Move on to Step 6	Calibrated flow rate hole blocked	Replace multivalve unit
		Move on to Step 6	LPG pressure sensor blocked	Replace pressure sensor
6	CHECK LPG PUMP EFFICIENCY	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	With the tester connected to the tester output, check the following at the LPG engine control unit in active diagnosis mode: correct operation of the LPG pump Check the operation of the LPG pump by running Test 1043AA See Test 1043A GPL TANK	Move on to Step 7	Anomalous pump power uptake	Replace the LPG pump
		Move on to Step 7	Wiring defective	Restore wiring See E5031 LPG FUEL SYSTEM ELECTRONIC MANAGEMENT

All versions

Engine judders when car is in motion and is not efficient.

STEP	OPERATIONS TO BE CARRIED OUT	TEST RESULTS
0	PRELIMINARY CHECKS	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the following, in order: condition of the air intake circuit; that there are no faults in the air filter; the seal of the diesel pipes; no obstructions in the catalytic converter; that there is no water, petrol, paraffin or dirt in the fuel tank and fuel filter; battery earth terminal fastening.	Move on to Step 1	Air intake circuit faulty	Renew the air intake circuit
			Air filter blocked	Replace the filter element Op. 1048A14 AIR CLEANER FILTERING ELEMENT - REPLACE.
			Leaks from diesel pipes	Eliminate the leaks
			Water, petrol, paraffin or dirt found to be present	Clean the tank and pipes and replace the filter element Op. 1044B20 FUEL FILTER FILTERING ELEMENT - REPLACE
			Catalytic converter obstructed	Replace the catalytic converter Op. 1080B62 CATALYTIC CONVERTER - R + R
			Battery earth terminal insecure	Secure battery earth terminal
1	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Connect the tester to the tester output. Check: that there are no errors in the control unit; the plausibility of the parameters; correct operation of the switch on the clutch pedal.	Move on to Step 2	Error detected in the control unit	Continue following the instructions for the tester
			Parameters not plausible	Continue following the instructions for the tester
			Clutch switch defective	Replace clutch switch
2	ROAD TEST USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Carry out a road test by reproducing the conditions in which the fault occurs, keeping the tester connected. Check: that there are no errors in the control unit; parameter plausibility.	Move on to Step 3	Error detected in the control unit	Continue following the instructions for the tester
			Parameters not plausible	Continue following the instructions for the tester
			No communication with the control unit	Restore the connection between the engine management control unit and the diagnostic connector See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT
3	CHECK ON CORRECT OPERATION	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check that the fault is no longer present	End of diagnosis	Fault persists	Replace the engine management control unit Op. 1060G80 DS ELECTRIC INJECTION CONTROL UNIT - R R

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Parts & tools for this job For 2002 Fiat Ducato

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