1995 Chevrolet Blazer 95 Blazer no one can fix

I need some help here 95 blazer 4x4 w Vin it has a really weird issue no one can seem to figure out. On start up fires right up no problems after running for about a minute it starts this weird lope at idle it will start struggling out of nowhere almost die and then go to a normal idle then it repeats. If you let it sit and idle it will always run like that. When you get it out on the road it pretty much looses all power and bairly putts then a massive power surge like it comes back to life. Now if you hold in on the throttle like normal and don't let out eventually it will run almost normal with it still being slightly sluggish and a bit of a missfire. From there on as long as it isn't shut off it will stay like this but once shut off it does it all over again. It doesn't change when it's hot or cold. Now as far as what I have personally replaced fuel pump injectors high pressure feed line to injectors fuel filter plugs (at least a half a dozen times because it seems to run rich) wires complete distributor coolant temp sensor egr valve throttle posision. The high pressure lines to the injectors as you probably know like to Crack over time we'll even after that and everything else was replaced literally no change at all. Fuel pressure and compression I tested a while back were within specs of what my Hanes manual had said it would be. The 221k engine still feels as if it has a lot of life in it with no oil leaks and not even the slightest tick but you can tell something dumb is making it do this. It's almost like driving down the road under steady throttle it falls on its face gets back up and falls back down then someone flips a switch and she's ready to go. This thing has been driving me nuts for over a year and for some reason I choose to use it as my daily even if it's gas mileage and running conditions and much less than appreciated.