Yeah I've looked into the GT40 but only place that would sell it that comes to mind is Super Cheap Auto - their website says they sell it but I've never seen it in store; I'll ask next time I'm there.

i have a bosch GT40 coil and it works great ,and they arent too bad on price ,mine is the GT40R which is the resistor type

and plus it says GT40R so its sounds fast!!

Hi diymark

I use LUCAS Cold color barrel type ignition coil, no matter it is now about 5 yrs no problem, and also i have heard LUCAS cold color coil is used in high performance cars and rallying too, but i don't know exactly.

the voltage ratio is bit high than stock coil on this as i remember

thanks
Regards
sumith

Ok, a new rotor, cap and leads later the car worked great and idled higher too (old leads were pretty bad).

However, the coil constantly sparked the to (-) terminal with a faint spark and sparked occasionally to the (+) terminal with a big thick spark.

Then all of a sudden the engine died and as it turned over slowing down it would spark to the (+) terminal from the HT terminal with huge full power sparks.

I put a DMM on the coil and I get 13.8K and 1.3

So now looks like I need a new coil - anyone have any ideas of a "performance" one to use?

yeah i changed everything, Coil, points ballast resistor and the last thing was the leads and it fixed the problem, give it a go and let me know.

Now you mention it, when I tried my old (circa 1979 coil) the car barley ran (bad coil) but it did in fact still short out too.

So, I will try new leads first as they are cheaper than a coil (I was thinking of getting new ones soon anyway) - but if I have to, I'll buy a new coil in the end.

Hmm, while tuning my carbs and doing WOT runs I could have revved the engine and the extra voltage put out by the alternator could have "over voltaged" and caused the crack - so one forum I read tells me...is this even possible - doesn't make sense to me.

I will check/adjust my voltage regulator.

EDIT: Does any one have readable (1200 wiki ones are hard to read) instructions to adjust the voltage regulator?

ive had that problem before! a few years ago now.

I replaced the coil and it still did it, replacing the leads did the trick!

I think somebody else posted a question about this problem not long ago.

Yeah its definitely the coil cap that leaks. Must be cracked as it shorts from the negative terminal to the center (high voltage terminal). You can see how the arcing has turned the edges of the cracks to like powder.

Looks like another coil it is - which sucks because this one was a brand new $50 Bosch coil with only 500Km put on it!!!

Hi diymark

It may be the coil it self leaking spark or might be cracked coil cap which going to the distributor ? check any crack on those two probably it will be the coil

thanks
Regards
sumith