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

Well after this im going to be trickle charging the battery tonight and then having it load tested tomorrow first thing.
All the below voltages were taken while turning the motor over attempting to start it. This was immediately after the battery read 12.1V with key off and not under load.
Battery power = 8.4V
Power to coil + = 7.2V
Power from negative coil to ground = 1.8V
Power to ignition(red wire) = 8.4V
Power from ignition(brown wire) = 7.7v
Ecu case voltage(case to ground)= 1.5 millivolts

The reason im load testing the battery tomorrow is because the damn thing isnt sending enough damn power through the systemin the first place during the starting process. So i cant expect any of my other readings to be proper without getting what they need. This would also explain why the 12v jumper wire to the coil didnt work either, because it was never 12v. Will update again tomorrow morning. Also nm9 ill check ur test after i find out about this battery. Thanks for all the help so far guys. Greatly appreciate it.