72928 - X01 EXCESSIVE FUEL CONSUMPTION

The engine seems to be running smoothly, but the fuel consumption is higher than ever before.
The fuel consumption figures in the technical documentation have been defined during the couse of homologation tests in accordance with directive 93/116/CE.These tests simulate an urban cycle and an average non-urban cycle and therefore may not be representative as fuel consumption depends a great deal on driving styles.
STEPOPERATIONS TO BE CARRIED OUTTEST RESULTS
0PRELIMINARY CHECKSALL OKPROBLEMS ENCOUNTEREDACTION
Check the following conditions:

  • condition of the air filter;
  • Check the exhaust circuit paying particular attention to any obstructions in the pipes
Move on to Step 1. Filter element dirty or damaged1. Replace the filter element    See in Op. 1048A14 air cleaner filtering element - replace.
2. Outlets obstructed2. Replace the complete exhaust pipe    See in Op. 1076B12 exhaust pipe assembly - r+r emission control versions
3. Exhaust silencers obstructed3. Replace the silencers
1CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Connect the Examiner diagnostic equipment to the diagnostic connector and check the following at the engine management node:in errors ambient

  • that there are no faults;
in parameters ambient

  • the plausibility of all the parameters.
Move on to Step Error detected in the control unitContinue following the instructions for the diagnostic equipment
2FUEL PRESSURE CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check that the fuel supply pressure corresponds to the recommended figure     See in Op. 0510C10 FUEL SYSTEM - Check DELIVERY PRESSUREMove on to Step Pressure not correct: pressure regulator faultyReplace the fuel pump assembly    See in Op. 1040A70 SUBMERGED PUMP ASSEMBLY complete with level gauge - R.R.
3INJECTOR SEAL CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Disconnect the injector ramp from the manifold, disconnect the electrical connections for the injectors, activate the fuel pump in active diagnosis and check that the injectors do not drip at the recommended operating pressureMove on to Step One or more injectors leakingReplace the injector(s)    See in Op. 1056B70 INJECTOR (one) - R.R. with fuel manifold pipe removed - Includes seal replacement
4TIMING CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check that the valve gear timing is correctMove on to Step Timing not correctRestore the correct timing    See in Op. 1032B14 TOOTHED timing BELT - R.R. for timing adjustment or replacement on versions with air conditioning
5CHECK ON CORRECT OPERATIONALL OKPROBLEMS ENCOUNTEREDACTION
Check that the fault is no longer present