So here is the basic of what is happening so far:
I imported a car NZ->US and it arrived about three months ago, it ended up waiting about 9 months to be exported because Covid yada yada.
Car arrives, runs great but doesn't pass emissions and needs a new battery and radiator. Turns out a new fuel pump helps it pass emissions, but quickly dies again, so I wire fuel pump directly from battery and get a new upgraded walbro 255.
Car is good for about a month, then on my moms birthday it starts being sputtery, and I ignoring long enough to finish out the day, but by the end of the day its pretty bad and the next day it turns over but doesn't start.
I change out the spark plugs and fuel filter, confirm each plug is getting spark, and fuel is being delivered at 50psi on start up, check all fuses, they're fine. I do a comp test (even though it is below freezing on a cold engine and get between 85 and 90psi on every cylinder. I even disconnect the cat just to make sure its not that being clogged that is the problem. The tank has enough fuel to fully submerge the pump, I set the timing back when I was doing emissions, and the CAS to make sure it wasn't broken. AFM is getting 12v.
Is there any thing else I could do to make it run before taking it to a shop? Trying to check all the cheaper solutions before having to think about a rebuild.