Just a question

Getting ready to replace the CPI unit on my 92 s10 blazer and I've noticed that everywhere and everyone tells me that I have to replace the entire CPI unit and not individual parts. Planning on going out and getting a entire new unit but was just wondering exactly why do you have to replace the entire unit????

You don't! You can service the regulator, pressure line and return line separately for substantially less money. If the injectors have a problem, or the lines to the intake ports, it might be worthwhile replacing the entire unit though.