DIS coil keeps burning out

I got a cutlass calais supreme a few months back and after about a week the distrubutorless ignition coil burned out so I bought another one and it lasted about a month before the car starting bucking bad then the coil melted and started oozing grey stuff out the top, so i went and got one at the scrap yard this time and it wont start at all now, just cranks and cranks.. I'm thinking maybe there is a bad wire or somthing but before i go get a whole new chassis I was wondering if you guys had any ideas? I gave it a tune up right when i got it (plugs, wires, fuel and air filters, oil change) the plugs are correctly gapped and wires are at spec resistance. I've been looking all over the chassis and everything looking for anything burned out but yet to visually see anything.