Maybe you cracked the wire to one of your camshaft position sensors. Easy to do when you are fussing over the stuff around the plenum. Those wires at this time are brittle from age.
My car is bog standard too, and I just went through it. Changed my injectors. Same thing. Running rough, blowing insane clouds of smoke. There are no codes when it first happens and is intermittent.
Oh it drove me insane, cause I thought it was fuel related. I started with the fuel sender unit and the filter in there, cleaned the tank, and then moved onto changing the o-rings in all the quick release clips for the fuel lines. I tried different injectors like you, and a new throttle position sensor. I finally sent my computer overseas to Kevin Stigant in Perth, only to find there was nothing wrong with it.
Eventually I could not even start the car. Kevin told me check the wiring. I found the crack just back from the camshaft position sensor, under the first bit of tape, cause it was the obvious place to look.
The thread for the whole ordeal is here.
https://forums.justcommodores.com.au/threads/fuel-sender-unit.278951/
I could have saved myself such grief and muchos $$$ with a dab of solder, ha ha. Hope it saves you.
I have tried out heaps of injectors in my car cause of this problem, by the way.
The contributors here know what they are talking about. I hope I can shout them all a beer some day. (Thanks to everyone, over the last few years my car went from total wreck to being 100% problem free, as it came from the factory. Took a few years, but I just got there a few days ago. Really appreciate.)
But I bought some cheap ones from Aliexpress, cause I am busted up.
They are indistinguishable from the originals in any way, cause I was dissecting to find the issue.
They were better than the originals cleaned up by myself, and originals cleaned up at an injector shop with new filters fitted (you can get the wee filters from Aliexpress, in the outboard motor section, cause it is hard to get the originals out without them disintegrating this far down the track).
They work awesome once you fix that wire ha ha. Motor sounds so crisp once the fuel system is clean and you put brand new ones in.