well I have a no spark prob. on my sammi, nothing coming out of the coil(well a little spark, barely noticable) On the neg. side of the coil (with the positive wire unattached) it is "grounding", this is not right.  To better explain, the coil has 2 leads running to it, pos. and neg., with the neg. wire hooked up(lead to coil) and the pos. wire unhooked I can attach  my multimeter pos to pos(coil lead) and neg(m.m.) to neg(coil lead) and get a good 12 volt signal.  The coil should not be acting as a ground(all the time I think at least)What can cause this?Also checked coil wire from coil to distrib.,  power is leaving the coil which is also a good sign 12 volts with ign. on.Something is "grounding"  this coil making it not fire like it is supposed to.  Fuse is good, ALL grounds are good, distributor is turning, timing is perfect, coil is getting good 12 volt power.  This was an all of a sudden thing, it just quit on me.  Can i run 2 new leads from coil directly to the distributor? or any other ideas

I know you said all grounds are good but I will just tell you my what  problem was. The factory ground from the back of the distributor to the firewall is'nt nearly a large enough guage. After time and adding in any sort of extra electronics quickly overloaded that little wire. It did not burn up like you would think either. Added a large ground strap from the motor to the firewall and she started right up. It sounds like you have done alot of testing wich I did not though. Good luck!

Is it electronic ignition or points ?
You might have to replace the points,
otherwise, if it's electronic, the coil is
getting charged, that's why it's sparking,
but the coil might bad too, find a known
good coil and test, or better yet, use your
Ohm meter to test the resistance of the coil