Coil packs just don't last forever and ever and ever etc etc etc....
No matter how much you want to tape them/silcone/glue/make love to/etc, eventually THEY ARE GOING TO DIE!!!!!!!!!!!!!!!
Just replace them......
if you can't afford splitfires, (and they are shitloads cheaper thah OEM crap) then jump on ebay or google and buy an inferior (usually) cheaper alternative