22 · Diagnostics

Engine starts with difficulty

Make: Fiat
Model: Croma Factory Service Manual
Year: 2005–2010
Section: Starting › Engine starts with difficulty

‹ Prev Engine does not start (under any circumstances)Next › Engine starts, and cuts out straight away

Fault diagnosisEngine starts with difficulty

ENGINE STARTS WITH DIFFICULTY

1.9 JTD 8v, 1.9 JTD 16v, 2.4 JTD 20v

The customer complains of: Engine starting poor, the starter motor works normally.

0	PRELIMINARY CHECKS	All OK	Problems encountered	Operation
		Results of the tests
	Check that the engine oil level is correct Op. 0010T11 ENGINE OIL - CHECK LEVEL AND TOP UP, IF NECESSARY Check that the air intake/vacuum circuit is working properly See Test 1048OA AIR INTAKE/VACUUM CIRCUIT CHECK Check the condition of the fuel supply circuit and make sure that it is working properly See Test 1040OA FUEL SUPPLY CIRCUIT CHECK	Move on to Step 1	Oil level incorrect	Restore the correct engine oil level Op. 0010T11 ENGINE OIL - CHECK LEVEL AND TOP UP, IF NECESSARY
1	AMBIENT PARAMETERS CHECK	All OK	Problems encountered	Operation
	Select the following control unit at the diagnostic equipment: EDC16C39 Diesel electronic injection control unit. Check the value of the following parameters: . Battery voltage . Objective Diesel pressure . Measured Diesel pressure . Atmospheric pressure . Engine rpm . Engine coolant temperature See Test 5530BB BATTERY VOLTAGE CHECK See Test 1060GH DIESEL FUEL PRESSURE CHECK See Test 1060GD ATMOSPHERIC PRESSURE CHECK See Test 1060GI ENGINE SPEED CHECK See Test 1060OE CHECK ON OPERATION OF COOLANT TEMPERATURE SENSOR	Move on to Step 2
2	PARTICLE FILTRATION SYSTEM CHECKS	All OK	Problems encountered	Operation
	Check that the DPF system is working properly See Test 1080BE PARTICULATE FILTER SATURATION CHECK	Move on to Step 3
3	PREHEATING RELAY ACTIVE DIAGNOSIS	All OK	Problems encountered	Operation
	Carry out the active diagnosis of the preheating relay, checking that the result is positive The check on the following system is only necessary if the outside temperature is below 0 °C.	Move on to Step 5	The result of the active diagnosis is negative	Move on to Step 4
4	HEATER PLUGS CHECK	All OK	Problems encountered	Operation
	Check that the heater plugs are working properly See Test 5520CA GLOW PLUGS FUNCTIONAL TEST	Move on to Step 5
5	ELECTRICAL EQUIPMENT CHECK	All OK	Problems encountered	Operation
	Check that the fuses F1 (the last one at the bottom of the vertical row) and F20 (the first one on the right of the lower row) have not blown	Move on to Step 7	Fuse F1 has blown	Restore the connections or, if necessary, replace the junction unit in the engine compartment Op. 5505A13 ADDITIONAL JUNCTION UNIT IN ENGINE COMPARTMENT - R.R.
		Move on to Step 7	Fuse F20 has blown	Move on to Step 6
6	DIESEL PREHEATING FUSE CHECK	All OK	Problems encountered	Operation
	Check the circuit for the protective fuse for the diesel preheating relay	Move on to Step 7
7	DIESEL PREHEATING RELAY CHECK	All OK	Problems encountered	Operation
	Check the diesel preheating relay circuit	Move on to Step 8
8	HIGH PRESSURE CHECK	All OK	Problems encountered	Operation
	Connect the diagnotsic equipment to the diagnostic socket. Check that the diesel pressure parameter is correct See Test 1060OD INSPECTION OF THE HIGH PRESSURE FUEL CIRCUIT	Move on to Step 16	Pressure not correct	Move on to Step 9
9	LOW RETURN PRESSURE CHECK	All OK	Problems encountered	Operation
	Check that the pressure in the return pipe to the tank is less than 1 bar See Test 1060OA CHECK ON RETURN LOW PRESSURE FUEL CIRCUIT	Move on to Step 10	Pressure above the maximum limit: return pipe to the tank obstructed	Repair the pipe, if necessary, replace it
10	LOW SUPPLY PRESSURE CHECK	All OK	Problems encountered	Operation
	Check as described in the test that the diesel pressure between the filter and the pressure pump is between 2 and 3 bar See Test 1060OB CHECK ON SUPPLY LOW PRESSURE FUEL CIRCUIT	Move on to Step 16	Pressure below the minimum limit or above the maximum limit	Move on to Step 11
11	LOW SUPPLY PRESSURE CHECK	All OK	Problems encountered	Operation
	Constrict the return pipe from the pressure relief valve and carry out the test again with the pipe constricted, checking that the filter outlet pressure remains below 2 bar	Move on to Step 12	Pressure rises to 5 bar: pressure regulator valve on filter mounting incorrectly adjusted	Replace the valve Op. 1060OB CHECK ON SUPPLY LOW PRESSURE FUEL CIRCUIT Op. 1044B10 FUEL FILTER ASSEMBLY - R + R OR REPLACE
12	LOW SUPPLY PRESSURE CHECK	All OK	Problems encountered	Operation
	Check that the difference in pressure upstream and downstream of the filter is less than 1 bar	Move on to Step 13	Difference in pressure more than 1 bar	Replace the diesel filter cartridge Op. 1044B20 FUEL FILTER FILTERING ELEMENT - REPLACE
13	LOW SUPPLY PRESSURE CHECK	All OK	Problems encountered	Operation
	Check that the supply pump pressure at the filter inlet is more than 2.2 bar	Move on to Step 16	Pressure below 2 bar	Move on to Step 14
14	LOW SUPPLY PRESSURE CHECK	All OK	Problems encountered	Operation
	Measure the difference in pressure between the electrical pump outlet and the filter inlet checking that it is less than 0.3 bar	Move on to Step 15	Difference in pressure more than 0.3 bar	Replace the pipe
15	LOW SUPPLY PRESSURE CHECK	All OK	Problems encountered	Operation
	Check as described in the test that the pump supply voltage is equal to 12V and that the current uptake is between 2 and 10 Amps	Move on to Step 16	Voltage less than 12 volt	Check electrical wiring See 1040AA SUPPLY VOLTAGE AND ABSORPTION CURRENT CHECKS
			Current greater than 10 A: pump defective	Replace the fuel pump assembly See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT
			Current less than 2 A: pump obstructed	Replace the fuel pump Op. 1040A70 SUBMERGED PUMP ASSEMBLY COMPLETE WITH LEVEL GAUGE CONTROL - R + R and clean the fuel tank Op. 1040A70 SUBMERGED PUMP ASSEMBLY COMPLETE WITH LEVEL GAUGE CONTROL - R + R
16	CHECK CORRECT OPERATION	All OK	Problems encountered	Operation
	Replace the DRV high pressure regulator Op. 1060E50 PRESSURE REGULATOR ON PRESSURE PUMP - R.R. and check that the fault is no longer present	End of diagnosis	Fault persists	Move on to Step 17
17	CHECK CORRECT OPERATION	All OK	Problems encountered	Operation
	Replace the high pressure pump Op. 1060E10 DIESEL INJECTION PRESSURE PUMP - R.R. and check that the fault is no longer present	End of diagnosis	Fault persists	Move on to Step 18
18	CYLINDER COMPRESSION CHECK	All OK	Problems encountered	Operation
	Carry out the cylinder compression check Op. 0520G15 COMPRESSION TEST - CHECK WITH EXAMINER WITH SPARK PLUGS/INJECTORS REMOVED	Move on to Step 20	Cylinder compression insufficient	Move on to Step 19
19	CHECK ON CAUSE OF INSUFFICIENT COMPRESSION	All OK	Problems encountered	Operation
	Carry out Op. 1016C10 SINGLE CYLINDER HEAD - R.R. AND REPLACE GASKET to check the valve seal Check condition of cylinders/piston rings	Move on to Step 20	Valve seal insufficient	Overhaul the head Op. 1016E10 SINGLE CYLINDER HEAD, REMOVED - OVERHAUL
		Move on to Step 20	Cylinders/piston rings worn	Restore the seal
20	CHECK ON CORRECT OPERATION	All OK	Problems encountered	Operation
	Check that the fault is no longer present	End of diagnosis	Fault persists	Replace the engine management control unit Op. 1060G80 DIESEL ELECTRONIC INJECTION CONTROL UNIT - .R

‹ Prev Engine does not start (under any circumstances)Next › Engine starts, and cuts out straight away

Parts & tools for this job For 2005 Fiat Croma

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