22 · Diagnostics

Engine not running smoothly

Make: Fiat
Model: Multipla Factory Service Manual
Year: 1998–2010
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

The engine does not run smoothly in all conditions (load, speed, etc.). This problem is accompanied by noise and vibrations coming from the engine.

0	PRELIMINARY CHECKS	All OK	Problems met	Operation
		Results of the tests
	Preliminarily check: the seal of the fuel pipes and connectors the condition of the air intake circuit	Continue to Step 1	Fuel pipes damaged	Renew or replace the pipes (see Assembly 1040B)
			Air intake circuit component damaged	Replace the component (see Assembly 1048A)
			Air intake circuit component damaged	Replace the component (see Assembly 1048A)
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 faults in the engine management control unit plausibility of all the parameters	Continue to Step 2	An error is detected in the control unit	Continue according to the instructions for the diagnostic equipment
		Continue to Step 2	Lack of dialogue with the control unit	Restore the connection between the engine management control unit and the diagnostic connector ( See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT).
2	FUEL FILTER CHECK	All OK	Problems met	Operation
	Check the condition and the cleanliness of the fuel filter:	Continue to Step 3	Filter dirty	Replace the filter element Op. 1044B20 Restore the condition of the filter, the pipes and the heater device
	Check the condition and the cleanliness of the fuel filter:	Continue to Step 3	Filter faulty or damaged	Replace the filter Op. 1044B10
3	CHECK RETURN LOW PRESSURE	All OK	Problems met	Operation
	Check the pressure between the manifold and the return pipe to the tank See Test 1060A Check low pressure fuel circuit	Continue to Step 4	Pressure over 1bar: the return circuit to the tank is clogged	Eliminate any blockages in the return pipe or in the cage for the low pressure pump immersed in the tank
4	CHECK DELIVERY LOW PRESSURE	All OK	Problems met	Operation
	Check the pressure between diesel filter and high pressure pump See Test 1060B Check low pressure fuel circuit	Continue to Step 5	Leaks in circuit	Eliminate fuel leaks from low pressure circuit pipes/connectors
			Pressure less than 1.8 bar or difference in pressure between Test B and Test A less than 1 bar	Replace the fuel pump Op. 1040A70
			Pressure over 3.5 bar	Replace valve on diesel filter mounting Op. 1044B16
5	FUEL INJECTOR LEAK TEST	All OK	Problems met	Operation
	Check injectors for diesel leaks: See Test 1060C Check high pressure fuel circuit	Continue to Step 6	Leak detected from one or more injectors	Replace injector(s) Op. 1060F10
6	HIGH PRESSURE CHECK	All OK	Problems met	Operation
	Check diesel pressure parameter measured using diagnostic instrument: See Test 1060D Check high pressure fuel circuit	Continue to Step 7	Pressure reading below 150 bar	Replace high pressure pump Op. 1060E10
		Continue to Step 7	Leaks in circuit	Eliminate fuel leaks from high pressure circuit pipes/connectors
7	CYLINDER COMPRESSION CHECK	All OK	Problems met	Operation
	Carry out the cylinder compression test Op. 0510A10	Continue to Step 8	Compression values not correct	Restore the correct cylinder compression, e.g. by checking the injector seal ( Op. 1060F10)
8	VALVE CLEARANCE CHECK	All OK	Problems met	Operation
	Check that the valve tappet clearance is correct. Op. 1036H14	Continue to Step 9	Clearance not correct	Restore the correct valve clearance. Op. 1036H18
9	CHECKING CORRECT OPERATION	All OK	Problems met	Operation
	Check that the fault is no longer present	End of diagnosis	Fault persists	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 For 1998 Fiat Multipla

Links open Amazon search results in a new tab. As an Amazon Associate I earn from qualifying purchases.