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Fiat Doblò Factory Service Manual (2000-2010)22 · Fault diagnosis
22 · Diagnostics

Rich fuel system

Make
Fiat
Model
Doblò Factory Service Manual
Year
2000–2010
Section
Examiner › Rich fuel system
Fault diagnosisRich fuel system

RICH FUEL SYSTEM

Results of the tests
1CANISTER VALVE CHECKAll OKProblems metOperation
Check that the canister valve is not stuck openContinue to Step 2Canister valve stuck open

Repair or, if necessary, replace the canister Op. 1080E20

Continue to Step 6

2INTAKE AND EXHAUST SYSTEM LEAKAGE CHECKAll OKProblems metOperation

Check the blow-by circuit See Test 1072A

In particular, check that there are no leaks from the engine sump to the intake circuit

Continue to Step 3Leaks are present

Eliminate leaks from the system. Replace faulty parts if necessary

Continue to Step 6

3PETROL PRESSURE CHECKAll OKProblems metOperation

Turn the key to MAR and check fuel pump activates.

Whilst the pump is activated, check that the fuel pressure is not too high

Continue to Step 4High pressure: fuel pressure regulator setting not correct

Calibrate correctly.

Continue to Step 6

High pressure: fuel pressure regulator faulty

Replace the fuel pump Op. 1040A70

Continue to Step 6

4CHECK ON FUEL INJECTORSAll OKProblems metOperation

Check the mechanical seal of the injectors.

In particular, check that none of the injectors are stuck open

Continue to Step 5Injectors defective

Renew the correct seal for the injectors, if necessary replace them Op. 1056B70

Continue to Step 6

5UPSTREAM LAMBDA SENSOR CHECKAll OKProblems metOperation
Starting from Step 3 See table Z56 UPSTREAM LAMBDA SENSOR SIGNAL ERROREnd of diagnosis
6DELETING AND CHECKING ERRORAll OKProblems metOperation

Use a tester to cancel the errors in the control unit.

Carry out a road test and ensure the error does not recur

Continue to Step 7The fault persistsSee table Z50 MIXTURE STRENGTH ERROR
7CHECKING CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persists
Results of the tests
1CANISTER VALVE CHECKAll OKProblems metOperation
Check that the canister valve is not stuck openContinue to Step 2Canister valve stuck open

Repair or, if necessary, replace the canister Op. 1080E20

Continue to Step 5

2INTAKE AND EXHAUST SYSTEM SEAL CHECKAll OKProblems metOperation

Check the blow-by circuit, visually checking that there are no leaks from the engine sump to the intake circuit.

Also check, visually and by listening, that there are no leaks from the intake and exhaust systems

Continue to Step 3Leaks are present

Eliminate leaks from the system. Replace faulty parts if necessary

Continue to Step 5

3PETROL PRESSURE CHECKAll OKProblems metOperation

Turn the key to MAR and check fuel pump activates.

While the pump is active, check fuel pressure is not too high.

Turn the ignition off and check that the pressure does not fall by a more than 1 bar over a period of 15 minutes.

Continue to Step 4High pressure: fuel pressure regulator setting not correct

Replace the fuel pump Op. 1040A70

Continue to Step 5

The pressure falls by more than 1 bar in the established time: faulty injectors

Renew the correct seal for the injectors, if necessary replace them Op. 1056B70

Continue to Step 5

The pressure falls by more than 1 bar in the established time: leaks from the fuel pressure regulator

Replace the fuel pump Op. 1040A70

Continue to Step 5

The pressure falls by more than 1 bar in the established time: leaks from the non-return valve on the fuel pump

Replace the fuel pump Op. 1040A70

Continue to Step 5

4UPSTREAM LAMBDA SENSOR CHECKAll OKProblems metOperation
Continue according to the instructions for the See table Z56 UPSTREAM LAMBDA SENSOR SIGNAL ERRORContinue to Step 3
5DELETING AND CHECKING ERRORAll OKProblems metOperation

Use a tester to cancel the errors in the control unit.

Carry out a road test and ensure the error does not recur

Continue to Step 6The fault persistsContinue to Step 1
6CHECKING CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisThe fault persists

Parts & tools for this job For 2000 Fiat Doblò

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