|
STEP |
COMPONENT CONCERNED |
OPERATION TO BE CARRIED OUT |
OK (NO FAULTS DETECTED) |
FAULT DETECTED |
OPERATION |
|
1 |
Spark Plugs |
CORRECT SPARK PLUG USE CHECK Check that the spark plugs used are the correct ones |
Go to Step 2 |
The spark plugs used are not the correct ones |
Install the correct spark plugs |
|
2 |
Spark Plugs |
SPARK PLUG DAMAGE CHECK Check that the spark plugs are not damaged. In particular, check that: - the insulator is not broken (see Fig. 1 and Fig. 2) - the electrode is not deformed or broken (see Fig. 3, Fig. 4 and Fig. 5) - the electrode is not melted (see Fig. 6) - the electrode does not show signs of dirt from incorrect combustion (see Fig. 7) - there are no deposits (see Fig. 8) |
Go to Step 3 |
One of these problems found |
Replace the damaged spark plugs |
|
3 |
Spark Plugs |
SPARK PLUG APPEARANCE CHECK Check the appearance of the spark plugs. In particular, check that: - there is no rust (see Fig. 9 and Fig. 10) - the hexagonal nut is free of defects (see Fig. 11) - there are no cracks in the insulator caused by incorrect use of the spark plug tightening spanner (see Fig. 12 and Fig. 13) - there is no damage to the ignition coil insertion terminal (see Fig. 14) - there are no signs of burning on the spark plug insulators (see Fig. 15) |
Go to Step 4 |
One of these problems found |
Replace the damaged spark plugs |
|
4 |
Spark Plugs |
SPARK PLUG INSULATION RESISTANCE CHECK Using an insulation tester, check that the resistance is greater than 50 Ohm with a voltage of 1000 V applied between the metal shell and the insulator (see Fig. 16). |
Go to Step 5 |
Incorrect insulation |
Replace the damaged spark plugs |
|
5 |
Spark Plugs |
SPARK PLUG INTERNAL RESISTANCE CHECK Measure the resistance between the spark plug terminal and the central electrode. Check that the resistance is between 3 kOhm and 7.5 kOhm (see Fig. 17). |
Go to Step 6 |
Incorrect resistance |
Replace the damaged spark plugs |
|
6 |
Spark Plugs |
SPARK PLUG ELECTRODE CHECK Check that the electrode: - is not crushed (see Fig. 18) - has no abrasions (see Fig. 19) |
End of diagnosis |
One of these problems found |
Repair (see Fig. 20) or replace the damaged spark plugs |
FIG. 1
FIG. 2
FIG. 3
FIG. 4
FIG. 5
FIG. 6
FIG. 7
FIG. 8
FIG. 9
FIG. 10
FIG. 11
FIG. 12
FIG. 13
FIG. 14
FIG. 15
FIG. 16
FIG. 17
FIG. 18
FIG. 19
FIG. 20