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Old 04-23-2007, 02:09 PM   #1 (permalink)
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What are the symptoms of an ignition coil going bad? My car 68FB 289 with pertronix ignition starts great, stumbles/slightly misfires at around 20mph, then again at around 70mph or under hard acceleration.

I have an Edelbrock manifold and carb. I've swapped the plugs, wires, fuel filter but the problem persists. My plugs looked good. I did notice with the engine running that there was an arc from the bottom of the coil wire to the coil terminal while I was resnugging the wires on the distributor cap. Do coils gradually go bad or do they just die completely?
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Old 04-23-2007, 02:40 PM   #2 (permalink)
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Mine intermittintly would cut out and stall,under power and idling, then start again when it cooled. I don't recall it skipping. Swapped it out, all set.
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Old 04-24-2007, 08:47 AM   #3 (permalink)
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Sounds to me like maybe you have a loose connection. Jumper the plus side of the coil straight off the battery and see if there is any difference.

Also there is the possibility that the Pertronix is going bad.
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Old 04-24-2007, 01:29 PM   #4 (permalink)
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I'll jumper the plus side of the coil straight off the battery tonight. There's also a Pertonix voltage testing procedure on the web that I'll perform to see if the Pertronix is bad.
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Old 04-24-2007, 02:42 PM   #5 (permalink)
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At night or in a dark garage open the hood and whilst holding a rag start wiggling the plug wires etc and see if there is any arcing.

After the Honda dealer told me my motocycle needed cylinder head work I took it home and parked it for a year. One day in the evening I started it (or tried) and noticed a spark jumping from the plug connector to the cylinder head. 99 cents later with a new spark plug connector the bike ran like new.
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Old 04-25-2007, 12:02 PM   #6 (permalink)
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OK, I discovered that the Pertronix is bad. I remembered that I had the Pertronix in my 61 Tbird as well, swapped it over and the Mustang runs perfect. Thanks for all the suggestions guys. I appreciate it.
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