Turns over but will not fire, could it be the Anti-theft system?

2003 FORD MUSTANG
102,000 MILES • 3.8L • 6 CYL • 2WD • AUTOMATIC
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MELANDJOSH
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  • 1 POST
The tumbler broke in my ignition, so it was replaced and ever since it only starts when it wants to. Which isn't often. It has started three times in the last 7 days all three times drove and ran fine until it was shut off and key taken out then right back to the radio works all the lights come on. turns over but will not fire.
Aug 28, 2022 at 8:14 PM
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STRAILER
  • ✓Experienced Mechanic
  • 55,267 POSTS
Is the anti-theft light flashing when it will not start? If not, can you hear the fuel pump cycle on for about 5 seconds in the fuel tank when you don't crank the engine over?

Here are some guides to help us reset the alarm system and hard reboot instructions as well:

https://www.2carpros.com/articles/how-to-reset-a-security-system

and

https://www.2carpros.com/articles/car-not-running-advanced

You can try a hard reboot which is done by removing the negative side of the battery, with the cable loose from the negative side of the battery, hold it to the positive terminal for 1 minute this will discharge the memory capacitors in the BCM and PCM allowing the system to reboot.

Please go over these guides and instructions and let me know what you find.
Aug 29, 2022 at 4:52 AM
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