My 95 gt 5sp, wouldnt start after i left the key on(it would still turn over fine). The battery got a little weak i put a battery charger on it and it fired right up. The other day it wouldnt start again, just turns over no start. i pulled the coil wire off and held close to block it has orange spark. i put the charger on it again and it fired right up. could this be a weak coil, the PO put a msd coil on it?