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Fiat Multipla Factory Service Manual (1998-2010)22 · Fault diagnosis
22 · Diagnostics

Engine not running smoothly / (irregular operation)

Make
Fiat
Model
Multipla Factory Service Manual
Year
1998–2010
Section
Engine › Engine not running smoothly / (irregular operation)
Fault diagnosisEngine not running smoothly / (irregular operation)

ENGINE NOT RUNNING SMOOTHLY / (IRREGULAR OPERATION)

The engine does not run smoothly in all conditions (load, speed, etc.).

1.6 16v · BIPOWER

Engine judders when car is in motion and is not efficient when running on methane.

All versions

In particular, it is irregular with short but frequent flat spots

1.6 16v · BIPOWER

After the system components are replaced, the self-adjustment parameters must be zeroed to restore the values originally set in the factory to the control unit maps

Results of the tests
0PRELIMINARY CHECKSAll OKProblems encounteredOperation
1CHECK USING DIAGNOSTIC EQUIPMENTAll OKProblems encounteredOperation

Connect the tester to the tester output and check the following on the methane engine management control unit in error mode:

Check:

  • for faults in the methane control unit

Check whether the self-adjustment parameters have been zeroed after components have been replaced

Move on to Step 2 1Error detected in the control unitContinue following the instructions for the diagnostic equipment
Self-adjustment parameters not zeroedZero the self-adjustment parameters
2CHECK METHANE PRESSUREAll OKProblems encounteredOperation
3CHECK METHANE INJECTOR SEALAll OKProblems encounteredOperation
4CHECK METHANE INJECTORSAll OKProblems encounteredOperation
5CHECK ON CORRECT OPERATIONAll OKProblems encounteredOperation

All versions

Results of the tests
0PRELIMINARY CHECKSAll OKProblems encounteredOperation
1CHECK USING DIAGNOSTIC EQUIPMENTAll OKProblems encounteredOperation
2INJECTOR CHECKAll OKProblems encounteredOperation
3FUEL PRESSURE CHECKAll OKProblems encounteredOperation
4CYLINDER COMPRESSION CHECKAll OKProblems encounteredOperation
5CHECK ACCELERATORAll OKProblems encounteredOperation
6CHECK ON CORRECT OPERATIONAll OKProblems encounteredOperation
Check that the fault is no longer presentEnd of diagnosisFault persists

1.6 16v · GPOWER

The engine does not run smoothly in all conditions (load, speed, etc.).

In particular, it is irregular with short but frequent flat spots

Results of the tests
0PRELIMINARY CHECKSAll OKProblems encounteredOperation

Check:

  • LPG level sufficient
  • Leads properly fastened to battery
  • Wiring on engine correctly fastened to earth
  • Check that the supply and return pipes, LPG injectors side are correctly fitted
  • Check the seal of the LPG system using an electronic leak detector to locate any gas leaks.
Move on to Step 1 1Insufficient level of LPGRestore correct LPG level
Battery lead fastening incorrectRestore correct lead fastenings
Pipes on pressure regulator reversedRestore the correct connection
imperfect system sealRestore the correct seal
1CHECK USING DIAGNOSTIC EQUIPMENTAll OKProblems encounteredOperation

Connect the Examiner diagnostic equipment to the diagnostic connector and check the following at the LPG engine management control unit: in error mode

  • that there are no faults in the LPG control unit;
Move on to Step 2 1Error detected in the control unitContinue according to the diagnostic equipment instructions
2PUMP EFFICIENCY CHECK LPGAll OKProblems encounteredOperation
3PRESSURE SENSOR CHECK LPGAll OKProblems encounteredOperation
4CHECK LPG PRESSUREAll OKProblems encounteredOperation
5INJECTOR SEAL CHECK LPGAll OKProblems encounteredOperation
6INJECTOR CHECK LPGAll OKProblems encounteredOperation
7CHECK ON CORRECT OPERATIONAll OKProblems encounteredOperation

Parts & tools for this job For 1998 Fiat Multipla

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