Kevin -

I can only speak for an IO-550. Continental specifies that the fuel injection system be inspected and set up iaw SID97-3x. You need some specific equipment and the SID is very thorough in specifying how to do it. We have an A&P do this at the same time we check the compression, time the mags, etc. If I recall, we lost a IV on takeoff because the mixture was set too rich. When it comes to working on the engine, it is best to let an expert do it if one is not pretty well trained on their specific power plant.