'89 7.3 IDI
 

So awhile back I bought 1989 f350. It seemed to run ok other than smoking when decelerating or just at that "cruise" point when you aren't accelerating. Put your foot in it, and it seemed to burn clean. So I replaced injectors, bled the air out, and that cured the smoking. ( ebay special $149) No smoke anytime. Rough idle, but starts ok and runs down the road more or less ok. I've backtracked and re-bled the injectors, but no significant improvement. I tried turning the fuel pressure up, no love there either. Considering the vintage of the engine, I'm not sure I want to just flop out the necessary bucks to purchase a new pump to troubleshoot. So, has anyone been down this path, and if so, can ya give an old guy a bit of advice? I think I'll take a shot at the filters today and see if that helps smooth it out, but I really want to get this behind me and move on.
thanks
omg