2003 FORD MUSTANG spark plugs

REMOVAL AND INSTALLATION
Spark Plugs
Removal and Installation
CAUTION: It is important to twist the spark plug wire boots while pulling upward to avoid
possible damage to the spark plug wire.
CAUTION: Spark plug wires must be connected to the correct ignition coil terminal. Mark
spark plug wire (12286) locations before removing them.
1. Remove the air cleaner outlet pipe. For additional information, refer to Section 303 - 12 .
2. Using the special tool, remove the spark plug wires from the spark plugs using a twisting motion.
3. NOTE: Use compressed air to remove any foreign material from the spark plug well before
removing the spark plugs.
NOTE: If an original spark plug is reused, make sure it is installed in the same cylinder from
which it was taken. New spark plugs can be used in any cylinder.
NOTE: Left side shown, right side similar.
Remove the spark plugs.
SECTION 303-
07A: Engine Ignition — 3.8L 2003 Mustang Workshop Manual Special Tool(s)
Remover, Spark Plug Wire
303-
106 (T74P- 6666A)
Material Item Specification
Silicone Brake Caliper Grease
and Dielectric Compound
D7AZ-
19A331-A or equivalent ESE-
M1C171-
A Klj . 1 ba
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7. Inspect for normal burning.
zThis can be identified by light tan or gray deposits on the firing tip.
8. Inspect for pre- ignition.
z This can be identified by melted electrodes and possibly a blistered insulator. Metallic
deposits on the insulator indicate engine damage.
z Install a new spark plug.
9. Inspect for overheating. zThis can be identified by a white or light gray insulator with small black or gray brown
spots and a bluish- burnt appearance of the electrodes.
z This may be caused by engine overheating, the wrong type of fuel, loose spark plugs, too
hot a plug, low fuel pump pressure or incorrect ignition timing.
z Install a new spark plug. Klj . 3 ba
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SPECIFICATIONS
SECTION 303-
07B: Engine Ignition — 4.6L (2V) 2003 Mustang Workshop Manual General Specifications
Item Specification
Base ignition timing 10 degrees ±
2 degrees non- adjustable Firing order 1-3-7-2-6-5-4-
8 Spark plug gap mm (in) 1.32-
1.42 (0.052- 0.056) Spark plug type AWSF-
32PP
Torque Specifications Description Nm lb-
ft lb-
in Spark plugs 15 11 —
Coil on plug bolts 10 — 89 Klj . 1 ba
12003 Mustang Workshop Manual
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REMOVAL AND INSTALLATION
Spark Plug
Removal
1. Remove the ignition coil on plug. For additional information, refer to Ignition Coil — Coil On Plug
in this section.
2. NOTE: Use compressed air to remove any foreign material from the spark plug well before
removing the spark plugs (12405).
NOTE: If an original spark plug is used, make sure it is installed in the same cylinder from which
it was taken. New spark plugs can used in any cylinder.
NOTE: One spark plug is shown; others are similar.
Remove the spark plugs
3. Inspect for gap bridged. zThis can be identified by a deposit build up closing the gap between electrodes.
z This can be caused by oil or carbon fouling.
z Clean the spark plug.
4. Inspect for oil fouling. zThis can be identified by wet black deposits on the insulator shell bore electrodes.
z This can be caused by excessive oil entering the combustion chamber through worn
rings and pistons, excessive clearance between valve guides and stems, or worn or
loose bearings. Correct the oil problem.
SECTION 303-
07B: Engine Ignition — 4.6L (2V) 2003 Mustang Workshop Manual Klj . 1 ba
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8. Inspect for overheating.
zThis can be identified by a white or light gray insulator with small black or gray brown
spots and with bluish- burnt appearance of the electrodes.
z This may be caused by engine overheating, wrong type of fuel, loose spark plugs, too hot
a plug, low fuel pump pressure or incorrect ignition timing.
z Install a new spark plug.
9. Inspect for fused spot deposits. zThis can be identified by melted or spotty deposits resembling bubbles or blisters.
z This may be caused by sudden acceleration.
z Clean the spark plug.
Installation 1. Adjust the spark plug gap as necessary. Klj . 3 ba
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SPECIFICATIONS
SECTION 303-
07C: Engine Ignition — 4.6L (4V) 2003 Mustang Workshop Manual General Specifications
Item Specification
Ignition timing 10 degrees BTDC ±
2 degrees non-adjustable Firing order 1-3-7-2-6-5-4-
8 Spark plug gap mm (in) 1.32-
1.42 (0.052- 0.056) Spark plug type AWSF-
32EM
Torque Specifications Description Nm lb-
ft lb-
in Spark plugs 15 11 —
Ignition coil cover bolts 10 — 89 Klj . 1 ba
12003 Mustang Workshop Manual
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REMOVAL AND INSTALLATION
Spark Plugs
Removal and Installation
1. Remove the ignition coil- on-plug. For additional information, refer to Ignition Coil - On - Plug in this
section.
2. NOTE: Use compressed air to remove any foreign material from the spark plug well before
removing the spark plugs.
NOTE: If an original spark plug is used, make sure it is installed in the same cylinder from which
it was taken. New spark plugs can be used in any cylinder.
Remove the RH spark plugs.
3. Remove the LH spark plugs.
4. Inspect the spark plugs. Install new spark plugs as necessary. For additional information, refer to Section 303 - 00
5. Adjust the spark plug gap as necessary.
SECTION 303-
07C: Engine Ignition — 4.6L (4V) 2003 Mustang Workshop Manual Klj . 1 ba
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10. If the vehicle stalls in (D) or manual 2 at idle with vehicle at a stop, move the transmission range
selector lever to manual 1 position. If the vehicle stalls, see torque converter operation
concerns. For additional information, refer to Diagnosis By Symptom in this section. If the
vehicle does not stall in (D), refer to Diagnosis By Symptom in this section.
11. If the vehicle exhibits a vibration during the road test, complete the Road Test Evaluation Form. This form will aid the technician in determining the source of the vibration.
NOTE: The following is a list of common vehicle concerns that have been misdiagnosed as torque
converter clutch shudder. For diagnosis of the following items refer to the appropriate sections of the
workshop manual and the Powertrain Control/Emissions Diagnosis (PC/ED) manual.
zspark plugs - check for cracks, high resistance or broken insulators
z plug wires
z fuel injector - filter may be plugged
z fuel contamination - poor engine performance
z EGR valve - valve may let in too much exhaust gas and cause engine to run lean
z vacuum leak - engine will not get correct air/fuel mixture
z MAP/MAF sensor - incorrect air/fuel mixture
z HO2S sensor - too rich/lean air/fuel mixture
z fuel pressure - may be too low
z engine mounts - loose/damaged mounts can cause vibration concerns
z axle joints - check for vibration Torque Converter Road Evaluation Form
1) Does the Torque Converter
Engage/Disengage? Yes ·
GO to Step 2. No ·
REFER to Diagnosis By Symptom —
Torque Converter No Apply Routine
240/340 and Always Applied Routine
241/341 in this section for further
diagnosis information. Repair as
required, verify converter operation
and then continue. 2) Does vibration occur during 3-
4 or 4-3 shift at:
light, medium, or heavy throttle? Light ·
May be torque converter clutch
shudder. GO to Step 3. Medium ·
May be torque converter clutch
shudder. GO to Step 3. Heavy ·
Not torque converter clutch shudder
— converter does not engage due to
PCM strategy. REFER to Section 100 - 04 and
Diagnosis By Symptom —
Noise/Vibration Routine 254/354
in this section for further diagnosis. 3) Is the problem vehicle speed dependent Yes ·
Not torque converter clutch shudder Klj . 2 ba
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