2427479 - D10 ENGINE IDLE IRREGULAR
The engine is not running smoothly when idling; in particular, it does not maintain a constant, regular value as the load varies (e.g. when electrical devices are switched on).| Results of the tests | ||||
| 0 | PRELIMINARY CHECKS | All OK | Problems met | Operation |
|---|---|---|---|---|
Preliminarily check:
| Continue to Step 1 | Spark plugs dirty or defective | Replace the spark plugs Op. 5510D10 | |
| Leads defective | Replace the spark plug leads Op. 5510D14 | |||
| Air filter blocked | Replace the filter element | |||
| Fault in air intake circuit | Restore the correct operation of the intake circuit | |||
| 1 | CHECKING WITH DIAGNOSTIC EQUIPMENT | All OK | Problems met | Operation |
| Connect
the diagnostic equipment (Examiner or other instruments) to the
diagnostic socket. Check:
| Continue to Step 2 | 'Supply system' error detected | See table Z50 | |
| Another error dectected in the control unit | Continue following the instructions for the diagnostic equipment | |||
| Inconsistent parameter | Continue following the instructions for the diagnostic equipment | |||
| 2 | IDLE ACTUATOR CHECK | All OK | Problems met | Operation |
| Check that the system carries out the correct idle learning procedure | Continue to Step 3 | Irregular idling | Carry out the idle learning procedure correctly | |
| 3 | PETROL VAPOUR RECOVERY SYSTEM CHECK | All OK | Problems met | Operation |
| Check the condition and seal of the petrol vapour recovery pipes | Continue to Step 4 | Air seepage | Restore the correct seal | |
| Pipe from canister to solenoid broken | Replace the pipe | |||
| 4 | PETROL VAPOUR RECOVERY SOLENOID VALVE CHECK | All OK | Problems met | Operation |
| Carry out active diagnosis of solenoid See Test 5510CC Check that the ignition coils are working: | Continue to Step 6 | Solenoid not working | Continue to Step 5 | |
| 5 | SOLENOID VALVE ELECTRICAL CIRCUIT CHECK | All OK | Problems met | Operation |
| Check supply and earth of petrol vapour recovery solenoid | Continue to Step 6 | Solenoid valve faulty | Replace the solenoid valve Op. 1080E28 | |
| Connections not correct | Restore the connections | |||
| 6 | BRAKE SERVO AND PIPE CHECK | All OK | Problems met | Operation |
Check condition of:
| Continue to Step 7 | Brake servo pipe defective | Replace the pipe | |
| Brake servo defective | Replace the brake servo/pump assembly | |||
| 7 | CHECK ON FUEL PRESSURE | All OK | Problems met | Operation |
| Check the fuel supply pressure Op. 0510C10 | Continue to Step 8 | Insufficient fuel pressure: pipe obstructed | Eliminate the blockage; if necessary replace the pipe | |
| Low fuel pressure: clogged filter | Replace the pump assembly | |||
| Insufficient fuel pressure: regulator out of calibration | Replace the pump assembly | |||
| Low fuel pressure: defective pump | Replace the pump assembly | |||
| 8 | CHECK ON TIMING | All OK | Problems met | Operation |
| Check that the timing is correct | Continue to Step 9 | Timing not correct | Restore the correct timing | |
| 9 | CHECK ON CORRECT OPERATION | All OK | Problems met | Operation |
| Check that the fault is no longer present | End of diagnosis | Fault persists: control unit faulty | Replace control unit Op. 1056B82 | |