[Sparky dave]

This has been ongoing for a while now hasn’t it? Seems like you have been over many many possibilities, like trying to find it using pot luck almost. Sorry I’m not meaning to be rude I’d love to help you fix this. Not followed everything you have done but If it was my problem I’d go back to basics which will quickly tell you where your problem is as there is not much to the basic operation of these engines. So here goes back to basics

-Compression test and leak down test ( check your engine is actually capable of running correctly)
-Fuel pressure, no guessing you need to know what it is
-Ignition. The only wiring you need is a +12 wire directly from batt to distributor and a ground wire from distributor to battery. These can be temporary wired in for purposes of proving your wiring system

After these basic steps you will either find your problem or know exactly where your problem lies. Go back to basics until you find your problem then you can get technical when you know where to get technical. Hope this helps you get methodical in your faultfinding. Best of luck, Dave