88 YJ with 93 zj 4.0 blows coils
I have a 88 YJ I swapped a 93 ZJ 4.0 in over 120k ago. In the last few months it started having an issue with blowing coils. I vaguely remember it doing it right after I swapped it in. It currently blows one every month. I am at my witts end on this problem and have exhausted every thing I could think of and am looking for new ideas.
What I've done-
New cap, rotor, wires, plugs
Replaced capacitors in PCM, part of a different problem
I also read the tsb on it that mentions the resistor wire to keep it from happening? The part is no longer available so I wired in series to the + side of the coil a .8 ohm ballast resistor. I'm thinking maybe I just need to go up more? I'm also running the spade type coil.
My battery is older but I don't think it makes a difference.
The coil opens when it's hot and if you let it cool down for a while it will crank back up and start. It also occasionally explodes them. Also sometimes the coil is so hot it will instantly burn you. As in way hotter than the engine. Any ideas would be greatly appreciated.
1979 CJ5 408 AMC dana 60/14b, T18, d300, PSC hydro assist
1948 Willys CJ2a LS 4.8/sm465 scout 44's