No spark and i can only get 5V at the coil.

Have you tried a different coil? Is it possible this one has an internal short and is drawing current / voltage?

See my link above for my recent sad tale of woe.
That's one thing I'm on the way out the door to do right now if I can get motivated to leave my air-conditioned house.
Try some different used coils and see if mine is sucking too much current and causing a voltage drop at "start".
Probably not. But you never know on these old things.
I freaking hate summer. Wasp, heat, humidity, snakes, UV damage.
Have I left anything out Texas?
Youse guys in the Pacific Northwest have my envy.