Quote:
Originally Posted by scarceller
Were the coils the 964 black OEM coils that went bad? Those coils are very rugged and they rarely go bad, to have 2 of them go bad is unheard of.
What are ignition pre wires? Are these the wires that go from the coil to the center of the dizzy cap?
A coil can get cooked if it's over charged, like keeping constant 12vdc on the coil for very long periods of time. If you are using some after market ignition system I'd suspect possible issue in that setup? It's possible that when engine is OFF the coils still have power on them? Those OEM coils have about a 4millisecond charge time at 12vdc, means they only need to be on for 4ms at most to be fully charged. See this video I created a while ago to understand charge times on the 964 coils.
https://youtu.be/a7dFdIdsZeU
The coils will get super hot if overcharged, you should be able to hold and touch the coils case and not get burned with engine running. The can temp should remain below 140F at all times. If the coil can is above 180F it's likely being overcharged.
I also gave you the max dwell time of about 4ms, I'd double check the ignition system to see what it has max dwell set at? |
Thank you that is very helpful and I appreciate all the comments! I’ll do some testing on the old coils.
I can’t say I’m 100% satisfied since the whole situation is a bit odd. I also would have liked to do the 993 coil conversion since now I have 2 silver coils instead of the original 2 black Bosch ones. I have heard good things on that retrofit.
Ignition system is stock motronic nothing aftermarket other then Steve Wong tune.