coil pack keeps dying in first cyl

[BarberJ86]

I have a stock sr20det in an 240sx, the car has been running fine for a year. Latley it has been acting up. it started running on 3 cly. i narrowed it down to a dead coil pack. i swaped in a new 1 and it ran good for like 3 minutes, then it started to backfireing while underboost. shortly after the coilpack got really hot and started to melt. visually wiring looks fine. Is there anything that could be causing that 1 coil pack to blow? is there any way to check the ignition system with a voltmeter?

[punxva]

check the grounds for it

[koukimonster139]

did you get a new coil pack? did your first one start to melt like the one you replaced it with or did the first one just die?

[street_white180sx]

check the voltage on the coils see if u have a ground on one and signal from one if i correct the coils are triggered by the ground side. so u should only have battery voltage on one. if not u have an electrical problem.

[BarberJ86]

the first coil pack just died, second 1 melted. its only the first cylinder thats giving me issues. i ripped apart the coil pack harness and all the wiring looks fine. im gonna check the voltage this afternoon. is there just one 12v line that splits @ the coilpack harness, grounds tie together and get grounded to the block?

[BarberJ86]

Update. i rewired the coilpack harness, put in new plugs and changed out the coilpack again. im getting around 12v @ coilpacks and everything is getting a good ground. Car ran perfect for 10 minutes even under boost, then started firing on 3 cylinders. then i truned off the car waited about an hour. turned on car let it idle for about 10 minutes (on 4 cyl) then all the sudden it started firing on 3 clyinders and the #1 coil pack fryed and started to smoke. this is the 3rd dead coilpack from the same cyl. im have no idea what it could be if the car runs fine for 10 mins then all the sudden the #1 coilpack stops firing, gets hot, then goes up in smoke. any1 have any suggestions?