need help mk3 supra 87
so i have a 7mgte supra and it was running fine but then the battery had died. and my friend put the jumper cables on backwards. so now all it does is crank but its not getting any spark, so idk what the problem is. i tried changing the ecu and doesnt make a difference. any other idead? maybe the coil pack blew? idk can anyone help me?