Engine not running smoothly / (hesistant)

Make: Fiat
Model: Bravo Factory Service Manual
Year: 2007–2014
Section: Engine › Engine not running smoothly / (hesistant)

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Fault diagnosisEngine not running smoothly / (hesistant)

ENGINE NOT RUNNING SMOOTHLY / (HESISTANT)

1.4 16v

There is a (prolonged) fall in performance (flat spots) during acceleration

0	PRELIMINARY CHECKS	All OK	Problems encountered	Operation
	First, check: - the condition of the air intake circuit - correct earth connection of the coils and the control unit motor to the engine block See E5030 PETROL ENGINES ELECTRONIC MANAGEMENT - leads properly connected to battery	Move on to Step 1	Air intake circuit faulty	Restore the seal on the air intake circuit
			Control unit motor earth connection on the engine block is defective	Restore the correct earth connection
			Loose cables to the battery	Restore correct tightening
1	CHECK USING DIAGNOSTIC EQUIPMENT	All OK	Problems encountered	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; - parameter plausibility	Move on to Step 2	Error detected in the control unit	Continue following the instructions on the diagnostic equipment
		Move on to Step 2	Parameter not consistent	Continue following the instructions on the diagnostic equipment
2	FUEL PRESSURE CHECK	All OK	Problems encountered	Operation
	Carry out a road test, reproducing the conditions in which the fault occurs. Check the fuel supply pressure Op. 0520G46 FUEL SYSTEM - CHECK SUPPLY PRESSURE USING THE EXAMINER	Move on to Step 3	Pressure not correct: obstructions in the fuel supply pipe	Remove the obstructions in the fuel pipe, replace it if necessary
			Pressure not correct: tank not sufficiently ventilated	Restore the tank ventilation
			Pressure not correct: petrol pump damaged	Replace the petrol pump assembly Op. 1040A70 SUBMERGED PUMP ASSEMBLY COMPLETE WITH LEVEL GAUGE CONTROL - R + R
3	SOLENOID CANISTER CHECK	All OK	Problems encountered	Operation
	- With the Examiner in active diagnosis, check that the solenoid canister is working properly - Check continuity of wiring between engine control unit and solenoid canister See E5030 PETROL ENGINES ELECTRONIC MANAGEMENT	Move on to Step 4	Defective solenoid canister	Replace the solenoid
		Move on to Step 4	Wiring broken	Restore correct wiring
4	CORRECT OPERATION CHECK	All OK	Problems encountered	Operation
	Check that the fault is no longer present	End of diagnosis	The fault persists	Replace the engine management control unit Op. 1056B82 INJECTION/IGNITION SYSTEM E.C.U. (ONE) - R + R

1.4 16v TJet

There is a (prolonged) drop in performance (flat spots) during acceleration

0	PRELIMINARY CHECKS	All OK	Problems encountered	Operation
		Test results
	First, check: - the condition of the air intake circuit - correct earth connection of the coils and the control unit motor to the engine block See E5030 PETROL ENGINES ELECTRONIC MANAGEMENT - leads properly connected to battery	Move on to Step 1	Air intake circuit faulty	Restore the seal on the air intake circuit
			Control unit motor earth connection on the engine block is defective	Restore the correct earth connection
			Loose cables to the battery	Restore correct tightening
1	CHECK USING DIAGNOSTIC EQUIPMENT	All OK	Problems encountered	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; - parameter plausibility	Move on to Step 2	Error detected in the control unit	Continue following the instructions on the diagnostic equipment
		Move on to Step 2	Parameter not consistent	Continue following the instructions on the diagnostic equipment
2	SHUT OFF BYPASS AIR SOLENOID VALVE CHECK	All OK	Problems encountered	Operation
	Check that the solenoid valve is working properly by carrying out the See Test	Move on to Step 3	Solenoid valve stuck open	Replace the by-pass solenoid valve Op. 1048B58 TURBOCHARGER AIR BY-PASS VALVE - R.R.
			Wiring from engine control unit to solenoid valve defective	Restore correct wiring
			Signal from engine control unit not correct	Replace the engine control unit Op. 1056B82 INJECTION/IGNITION SYSTEM E.C.U. (ONE) - R + R
3	FUEL PRESSURE CHECK	All OK	Problems encountered	Operation
	Carry out a road test, reproducing the conditions in which the fault occurs. Check the fuel supply pressure by performing the See Test 1056BY FUEL SYSTEM SUPPLY PRESSURE CHECK and the See Test 1056BI FUEL SYSTEM RETURN PRESSURE CHECK	Move on to Step 4	Pressure not correct: obstructions in the fuel supply pipe	Remove the obstructions in the fuel pipe, replace it if necessary
			Pressure not correct: tank not sufficiently ventilated	Restore correct tank ventilation
			Pressure not correct: petrol pump damaged	Replace the petrol pump assembly Op. 1040A70 SUBMERGED PUMP ASSEMBLY COMPLETE WITH LEVEL GAUGE CONTROL - R + R
4	AIR/TEMPERATURE PRESSURE SENSOR CHECK	All OK	Problems encountered	Operation
	Check correct operation of the pressure sensor by carrying out the See Test 1056BU CHECK ON OPERATION OF PRESSURE SENSOR AND/OR INTAKE AIR TEMPERATURE SENSOR Check the continuity/insulation of the wiring between the sensor and the engine control unit	Move on to Step 5	Wiring between sensor and engine control unit with short circuit or open circuit	Restore correct wiring.
		Move on to Step 5	Sensor defective	Replace the sensor Op. 1056B54 INTAKE AIR PRESSURE/TEMPERATURE SENSOR - R.R.
5	TURBOCHARGING PRESSURE SENSOR CHECK	All OK	Problems encountered	Operation
	Check correct operation of the pressure sensor by carrying out the See Test 1064BA TURBOCHARGING PRESSURE CHECK Check the continuity/insulation of the wiring between the sensor and the engine control unit	Move on to Step 6	Wiring between sensor and engine control unit with short circuit or open circuit	Restore correct wiring.
		Move on to Step 6	Sensor defective	Replace the pressure sensor Op. 1056B44 AIR PRESSURE SENSOR - R.R.
6	CANISTER SOLENOID VALVE CHECK	All OK	Problems encountered	Operation
	With the Examiner in active diagnosis, check that the solenoid canister is working properly Check continuity of wiring between engine control unit and solenoid canister See E5030 PETROL ENGINES ELECTRONIC MANAGEMENT	Move on to Step 7	Defective solenoid canister	Replace canister solenoid valve Op. 1080E28 ENABLEMENT SOLENOID FOR FLOW OF FUEL VAPOUR TO INLET - R+R
		Move on to Step 7	Wiring broken	Restore correct wiring
7	CORRECT OPERATION CHECK	All OK	Problems encountered	Operation
	Check that the fault is no longer present	End of diagnosis	The fault persists	Replace the engine management control unit Op. 1056B82 INJECTION/IGNITION SYSTEM E.C.U. (ONE) - R + R

‹ Prev Gear engagement sensitivity poor Next › Engine not running smoothly / (losing power)

Parts & tools for this job For 2007 Fiat Bravo

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