Have your batteries load tested FIRST, then test FICM voltage. If all checks out, try the Rev-X, it work's wonders.
FWIW, I have sticky injectors based on which FICM I'm using. I have some FICM's I test on the truck where the stiction disappears, and some where I get it really bad. All read 48V at all three conditions too, brand new 880CCA batteries too.