72412 - D10 ENGINE IDLE IRREGULAR

STEPOPERATIONS TO BE CARRIED OUTTEST RESULTS
0PRELIMINARY CHECKSALL OKPROBLEMS ENCOUNTEREDACTION
First, check:

  • condition of the air filter;
  • the condition of the air intake circuit
Move on to Step 1. Air filter blocked1. Replace the filter element    See in Op. 1048A14 air cleaner filtering element - replace.
2. Fault in the air intake circuit2. Restore the correct operation of the intake circuit
1CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Connect the diagnostic test equipment (Examiner or other instruments) to the tester input.Check:

  • that there are no faults in the engine management control unit;
  • parameter plausibility
Move on to Step 1. "Fuel system" error detected1. Continue following the instructions in Table Z050
2. Another error detected in the control unit2. Continue following the instructions for the diagnostic equipment
3. Parameter not consistent3. Continue following the instructions for the diagnostic equipment
2PETROL VAPOUR RECOVERY SYSTEM CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check the condition and the seal of the pipe between the canister solenoid valve and the intake manifold 1. Air leaks1. Restore the correct seal
2. Pipe between solenoid valve and manifold damaged2. Replace the pipe
3PETROL VAPOUR RECOVERY SOLENOID VALVE CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Carry out the active diagnosis of the solenoid valveMove on to Step Solenoid valve not workingMove on to Step
4SOLENOID VALVE ELECTRICAL CIRCUIT CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check the petrol vapour recovery solenoid valve supply and earth (Wiring Diagram ) E5030 PETROL ENGINE ELECTRONIC MANAGEMENT Move on to Step 1. Solenoid valve faulty1. Replace the solenoid valve    See in Op. 1080E28 enablement solenoid for flow of fuel vapours to inlet - r+r
2. Connections not correct2. Repair the connections (Wiring Diagram ) E5030 PETROL ENGINE ELECTRONIC MANAGEMENT
5BRAKE SERVO AND PIPE CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check the condition of the brake servo vacuum pipes;Check the operation of the single-acting valve and the brake servo    Continue following the instructions in the test 3330DA Brake servo operational checkMove on to Step 1. Brake servo pipe defective1. Replace the pipe
2. Brake servo defective2. Replace the brake servo/pump assembly
6FUEL PRESSURE CHECKALL OKPROBLEMS ENCOUNTEREDACTION
2.4 20 V,2.0 TBCheck the fuel supply pressure    See in Op. 0510C10 FUEL SYSTEM - Check DELIVERY PRESSUREMove on to Step 1. Fuel pressure too low: pipe obstructed1. Eliminate the obstructions, if necessary, replace the pipe
2. Fuel pressure too low: pump defective2. Replace the pump assembly    See in Op. 1040A70 SUBMERGED PUMP ASSEMBLY complete with level gauge - R.R.
6FUEL PRESSURE CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check the fuel supply pressure    See in Op. 0510C10 FUEL SYSTEM - Check DELIVERY PRESSUREMove on to Step 1. Fuel pressure too low: pipe obstructed1. Eliminate the obstructions, if necessary, replace the pipe
2. Fuel pressure too low: pump defective2. Replace the pump assembly    See in Op. 1040A70 SUBMERGED PUMP ASSEMBLY complete with level gauge - R.R.
7PHASE TRANSFORMER SOLENOID VALVE CHECKALL OKPROBLEMS ENCOUNTEREDACTION
2.4 20 V,2.0 TBCarry out the active diagnosis of the phase transformer solenoid valveMove on to Step Solenoid valve not workingMove on to Step
8PHASE TRANSFORMER ELECTRICAL CIRCUIT CHECKALL OKPROBLEMS ENCOUNTEREDACTION
2.4 20 V,2.0 TBCheck the supply and earth for the phase transformer solenoid valve (Wiring Diagram ) E5030 PETROL ENGINE ELECTRONIC MANAGEMENT Move on to Step Connections not correctRepair the connections (Wiring Diagram ) E5030 PETROL ENGINE ELECTRONIC MANAGEMENT
9PHASE TRANSFORMER CHECKALL OKPROBLEMS ENCOUNTEREDACTION
2.4 20 V,2.0 TBCheck the operation of the phase transformer supplying the phase transformer solenoid avlve directly.The engine speed should vary considerably (very irregular idling)Move on to Step There are no speed variations: phase transformer stuckReplace the phase transformer    See in Op. 1036C40 VARIABLE VALVE TIMING on inlet camshaft in cylinder head - R and R with shaft removed
10TIMING CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check that the valve gear timing is correctMove on to Step Valve gear timing not correctRestore the correct valve gear timing
11CHECK ON CORRECT OPERATIONALL OKPROBLEMS ENCOUNTEREDACTION
Check that the fault is no longer presentFault persists control unit defectiveReplace the control unit    See in Op. 1056B82 Injection/ignition system CONTROL UNIT (one) - R.R.