I was offering to go through his injectors for him, guess that wasn’t apparent.imho, that's some awful advice to give a newb with no equipment on checking spray pattern or parts injectors to canibalize springs and shims from.
Injectiors on these motors are essentially a calibrated pressure relief valve. there's really no magic happening other than they perform best as a batch popping off at a consistent pressure and with the same pattern. no other magic happening there. the problem enters when the rebuilder is only concerned with cleaning up the parts and putting them back together to perform under general minimum guidelines. Unless the rebuilder is putting in new needles and nozzles(those are the wear items), you are throwing away money. currently who is doing that? Typ4(Russ), R&D, and maybe Conestoga(unconfirmed) are the only ones doing so. How do you know? the price would be a great indicator. The magic happens with the injection pump and that is why they should be replaced together at the same time. So, is it a good idea to change out a pump and injectors if you don't have issues? depends. key thing is your fuel mileage. anything close to 10mpg is a clear indicator you have pump and maybe injector problems. you can still be running smooth and have ****** mileage from an old pump. rough idle and rough operation are also urgent indicators of replacement. start with a mileage check from a few fillups to use as a baseline and a pic under the hood to show us ithe condition of the motor will help greatly too.
good luck