2003 FORD MUSTANG Workshop Manual

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FORD MUSTANG 2003  Workshop Manual 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. 
 C

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FORD MUSTANG 2003  Workshop Manual 4. Inspect for gap bridged. 
�zThis can be identified by deposit build up closing the gap between electrodes. 
�z This may be caused by oil or carbon fouling. 
�z Clean the spark plug. 
5. Inspect for

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FORD MUSTANG 2003  Workshop Manual 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

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FORD MUSTANG 2003  Workshop Manual 10. Inspect for fused spot deposits. 
�zThis can be identified by melted or spotty deposits resembling bubbles or blisters. 
�z This can be caused by sudden acceleration. 
�z Clean the spark plug. 
11

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FORD MUSTANG 2003  Workshop Manual 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

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FORD MUSTANG 2003  Workshop Manual DESCRIPTION AND OPERATION 
Engine Ignition 
Eight separate ignition coils (12029): 
�zare mounted directly above each spark plug (12405). 
�z are controlled by the powertrain control module (PCM) for

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