Let it set till this storm was past for about two days after filling it up and adding Howes diesel conditioner to it. Apparently that was a mistake,cause it wasn't ran right since. I cranked it up yesterday afternoon to ride to moms to check on my cows and her pond. Truck cranked as normal but smoked like crazy and had a really low idle,so I said "that's weird" and gave it some throttle,truck chugged,smoked,and popped. Not at all normal running for this truck I shut it down and popped the hood to look for what ever was ailing it,everything was normal looking. Next I drained the fuel filter,good clean fuel came out,so I replaced the filter anyhow. Cranked it back up after bleeding the air,ran the same. This time I kept it running. After about 1min of running the smoke,low idle,and popping went away and didn't return till I started it up to go to the shop this morning,same siht all over again except it took almost 10min to straighten up,after it did it ran fine for about three or four miles till I stopped at an intersection and the bad running started again. Now it sets in my shop,while I peer over in the engine bay scratching my head
I've checked the fuel pressur,7lbs
I've changed the fuel filter
I've cracked the injector lines to see if there was a dead cylinder,bad injector(s)
Fixin to install a clear line to check for air bubble
Any other thoughts before I snatch the pump off and injectors off to be checked,I'm open to any and all advice

93 D250 ,5 speed,4.11s,k&n autometer tach pyro trans boost guages,GDS 60mm h1c 14cm,honed 5x10,hplp/reg,1/8 timing,M+H M2 fuel pin, tims cooler tubz