no start

hi..have a 1984 380sl that will not start. car sat bout 2 months and battery was low. jumped started with battery charger follow-up. engine turns over strong but will not fire.replaced coil, distributor wire. ovp fuse is good(replaced). have 12v reading at positive coil terminal. o volt reading at negative coil terminal when leads connected. if i disconnect the wires at negative coil terminal i get a 12v reading. i'm lost as to what to check next. was thinking about the ignition pick-up in distributor.

thanks