Check the colour of the ceramic insulation around the central electrode: an even, light brown colour indicates the engine is in good condition and running at the right temperature.
Inspect the centre electrode for wear and check spark plug gap, which should be: 0.8+/-0.1 Mm.

Important
Check the gap between the central and side electrodes. Replace the spark plug if taken value is different from the specified one or the spark plug shows clear signs of carbon settling.
Important
Do not use spark plugs with inadequate thermal rating or incorrect thread length.
The spark plug must be securely installed.
If a spark plug is loose, it can overheat and damage the engine.
Spark plug type
Make: ngk
Type: mar9a-j


Remove the coil-spark plugs wires (1), loosening the screws (2) of both spark plugs.
Using the appropriate tool 88713.2877 To replace the spark plugs.


Place the coil-spark plugs wires (1) in the relevant seats and tighten the screws (2) to a torque of 10 nm (min. 9 Nm - max. 11 Nm) (sect. 3 - 3, Engine torque settings).



Checking valve clearances
Changing and cleaning the air filtersIgnition coils
Introduction
The engine control system of the diavel includes two ignition coils: one for
the horizontal cylinder and one for the vertical
cylinder. These coils are installed directly in the spark plug wells. A diode is
installed on the secondary winding inside the
coil, which prevents the un ...
Reassembly of the cylinder head
The exhaust side can be identified by the three threaded holes on the flange.
The intake side can be identified by the presence of four threaded holes on
the flange.
All the photos in this chapter refer to a vertical cylinder head.
Valve guide sealing rings
Position the cylinder head o ...
Dds diagnosis instrument
The main functions of the dds diagnosis instrument can be summarised as
follows:
Retrieval of errors (faults) of the ignition-injection system stored in
the engine control unit memory and their subsequent
deletion, if required.
Reading of engine parameters (rpm, coolant and air temperat ...