1991 740 regina no spark

[Snydur]

Hello all, long time lurker first time poster. I am the proud owner of a 200$ Volvo 740 that up until a week ago was going strong.cranks but no start, it did it intermittently and now its full time. Narrowed it down to no spark. I replaced the coil, control unit, radio relay, ignition switch and crank sensor. Upon diagnostics I found there is no spark coming from the coil so it isn't plugs or wires, when it did start it ran perfectly fine. Other oddball things I noticed is the power to the ignition ecu is on in accessory but once you crank it there is no more power to it. I'm really at my wits end with this car, any help would be useful