3233220 - Z52 LEAN FUEL SYSTEM

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Results of the tests
1INTAKE AND EXHAUST SYSTEM LEAKAGE CHECKAll OKProblems metOperation
Check the intake and exhaust system visually and by listening, to check that there are no leaks downstream of the MAP sensor/flow meter.

Also take into account:

  • blow-by circuit;
  • canister circuit, checking that the valve is not stuck open;
  • brake servo vacuum pipes;
  • injector O-rings.
Continue to Step 2 Leaks are presentEliminate leaks from the system. Replace faulty parts if necessary Continue to Step 5
2PETROL 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 low Continue to Step 3 Low pressure: fuel filter blocked/obstructed Replace the fuel pump Op.   1040A70  Continue to Step 5
Low pressure: supply pipe restrictions/leaksRenew or, if necessary, replace the pipes involved
Low pressure: pressure regulator defective Replace the fuel pump Op.   1040A70  Continue to Step 5
Low pressure: pressure regulator incorrectly calibrated Replace the fuel pump Op.   1040A70  Continue to Step 5
Low pressure: electrical problem in the fuel pump Restore correct connections. If necessary, replace the fuel pump Op.   1040A70  See   E5030  PETROL ENGINE ELECTRONIC MANAGEMENT Continue to Step 5
Low pressure: excess pressure valve stuck open Replace the fuel pump Op.   1040A70  Continue to Step 5
3CHECKING FUEL QUALITYAll OKProblems metOperation
Check that there is no water or other substances in the tank which is contaminating the fuel. Continue to Step 4 Impurities are present Clean the tank and fill with new fuel Op. 1040A24 Continue to Step 5
4UPSTREAM LAMBDA SENSOR CHECKAll OKProblems metOperation
See table   Z56  UPSTREAM LAMBDA SENSOR SIGNAL ERROR starting from Step 3 End of diagnosis-
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 6 The fault persists Continue to Step 0
6CHECKING CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persistsSearch for the fault starting from another symptom'