312000554 - D001 ENGINE NOT RUNNING SMOOTHLY / (HESISTANT)

There is a (prolonged) drop in performance (flat spots) during acceleration
Test results
0PRELIMINARY CHECKSAll OKProblems encounteredOperation

First, check:

  • the condition of the air intake circuit
  • Correct earth connection of the coils and the engine control unit on the engine block
    See E5030 PETROL ENGINES ELECTRONIC MANAGEMENT

  • Leads properly connected to battery
Move on to Step 11. Air intake circuit faulty2. Engine control unit earth connection on the engine block is defective3. Loose cables to the battery1. Restore the seal on the air intake circuit2. Restore the correct earth connection3. Restore correct tightening
1CHECK USING DIAGNOSTIC EQUIPMENTAll OKProblems encounteredOperation
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 21. Error detected in the control unit2. Parameter not consistent1. Continue following the instructions on the diagnostic equipment2. Continue following the instructions on the diagnostic equipment
2FUEL PRESSURE CHECKAll OKProblems encounteredOperation
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 CHECKMove on to Step 31. Pressure not correct: obstructions in the fuel supply pipe2. Pressure not correct: tank not sufficiently ventilated3. Pressure not correct: petrol pump damaged1. Remove the obstructions in the fuel pipe, replace it if necessary2. Restore the tank ventilation3. Replace the petrol pump assembly    Op. 1040A70 SUBMERGED PUMP ASSEMBLY COMPLETE WITH LEVEL GAUGE CONTROL - R + R
3CANISTER SOLENOID CHECKAll OKProblems encounteredOperation
With the Examiner in active diagnosis, check that the canister solenoid is working properlyCheck continuity of wiring between engine control unit and solenoid canister    See E5030 PETROL ENGINES ELECTRONIC MANAGEMENT Move on to Step 41. Defective solenoid canister2. Wiring broken1. Replace the solenoid    Op. 1080E28 ENABLEMENT SOLENOID FOR FLOW OF FUEL VAPOUR TO INLET - R+R 2. Restore correct wiring
4VARIABLE VALVE TIMING CHECKAll OKProblems encounteredOperation

Check:

  • Correct operation of variable valve timing, carrying out the
See Test

Check:

  • Continuity of the wiring
  • Correct operation of variable valve timing solenoid, carrying out the
See Test
Move on to Step 51. Variable valve timing defective2. Wiring broken3. Solenoid defective1. Replace the variable valve timing    Op. 1036B39 PHASE TRANSFORMER ON CAMSHAFT IN CYLINDER HEAD - R.R.2. Restore correct wiring3. Replace the variable valve timing solenoid    Op. 1056B48 PHASE TRANSFORMER ELECTROMAGNET - R.R.
5CORRECT OPERATION CHECKAll OKProblems encounteredOperation
Check that the fault is no longer presentEnd of diagnosisThe fault persistsReplace the engine management control unit    Op. 1056B82 INJECTION/IGNITION SYSTEM E.C.U. (ONE) - R + R