Subaru Legacy III (2000-2003 year). Manual - part 201

IG(H4SOw/oOBD)-6

IGNITION

SPARK PLUG

6) Remove spark plug with the spark plugs socket.

B: INSTALLATION

1. RH SIDE

1) Install in the reverse order of removal.

Tightening torque (Spark plug):

21 N·m (2.1 kgf-m, 15 ft-lb)

CAUTION:
The above torque should be only applied to 
new spark plugs without oil on their threads.
In case their threads are lubricated, the torque
should be reduced by approximately 1/3 of the
specified torque in order to avoid over-stress-
ing.

Tightening torque (Resonator chamber):

33 N·m (3.4 kgf-m, 24.6 ft-lb)

2. LH SIDE

1) Install in the reverse order of removal.

Tightening torque (Spark plug):

21 N·m (2.1 kgf-m, 15 ft-lb)

CAUTION:
The above torque should be only applied to 
new spark plugs without oil on their threads.
In case their threads are lubricated, the torque
should be reduced by approximately 1/3 of the
specified torque in order to avoid over-stress-
ing.

C: INSPECTION

Check electrodes and inner and outer porcelain of
plugs, noting the type of deposits and the degree of
electrode erosion.

1) Normal
Brown to grayish-tan deposits and slight electrode
wear indicate correct spark plug heat range.

2) Carbon fouled
Dry fluffy carbon deposits on insulator and elec-
trode are mostly caused by slow speed driving in
city, weak ignition, too rich fuel mixture, dirty air
cleaner, etc.
It is advisable to replace with plugs having hotter
heat range.

IG-00073

(A) Electrode gap

(B) Carbon accumulation or wear

(C) Cracks

(D) Damage

(E) Damaged gasket

IG-00023

( A )

( B )

( C )

( E )

( D )

IG-00024

IG-00025

IG(H4SOw/oOBD)-7

IGNITION

SPARK PLUG

3) Oil fouled
Wet black deposits show excessive oil entrance
into combustion chamber through worn rings and
pistons or excessive clearance between valve
guides and stems. If same condition remains after
repair, use a hotter plug.

4) Overheating
White or light gray insulator with black or gray
brown spots and bluish burnt electrodes indicate
engine overheating. Moreover, the appearance re-
sults from incorrect ignition timing, loose spark
plugs, wrong selection of fuel, hotter range plug,
etc. It is advisable to replace with plugs having
colder heat range.

D: CLEANING

Clean spark plugs in a sand blast type cleaner.
Avoid excessive blasting. Clean and remove car-
bon or oxide deposits, but do not wear away porce-
lain.
If deposits are too stubborn, replace plugs.

E: ADJUSTMENT

Correct it if the spark plug gap is measured with a
gap gauge, and it is necessary.

Spark plug gap: L

Without catalytic converter

0.7 — 0.8 mm (0.028 — 0.031 in)

With catalytic converter

1.0 — 1.1 mm (0.039 — 0.043 in)

NOTE:
Replace with new spark plug if this area (A) is worn
to “ball” shape.

IG-00026

IG-00027

IG-00028

L

( A )

IG(H4SOw/oOBD)-8

IGNITION

IGNITION COIL AND IGNITOR ASSEMBLY

3. Ignition Coil and Ignitor As-

sembly

A: REMOVAL

1) Disconnect battery ground cable.

2) Disconnect spark plug cords from ignition coil
and ignitor assembly.

3) Disconnect connector from ignition coil and igni-
tor assembly.

4) Remove ignition coil and ignitor assembly.

B: INSTALLATION

Install in the reverse order of removal.

Tightening torque:

6.4 N·m (0.65 kgf-m, 4.7 ft-lb)

CAUTION:
Be sure to connect wires to their proper posi-
tions. Failure to do so will damage unit.

C: INSPECTION

Using accurate tester, inspect the following items,
and replace if defective.
1) Primary resistance
2) Secondary coil resistance

CAUTION:
If the resistance is extremely low, this indicates 
the presence of a short-circuit.

Specified resistance:

[Primary side]

Between terminal No. 1 and No. 2

0.73 

Ω±

Ω±

Ω±

Ω±

10%

Between terminal No. 2 and No. 4

0.73 

Ω±

Ω±

Ω±

Ω±

10%

FU-00009

IG-00074

IG-00075

IG-00038

IG-00038

IG-00050

4

3

2

1

IG(H4SOw/oOBD)-9

IGNITION

IGNITION COIL AND IGNITOR ASSEMBLY

[Secondary side]

Between (A) and (B)

12.8 k

Ω±

Ω±

Ω±

Ω±

15%

Between (C) and (D)

12.8 k

Ω±

Ω±

Ω±

Ω±

15%

3) Insulation between primary terminal and case:
100 M

Ω

 or more.

IG-00039

(C)

(A)

(D)

(B)