I've done a lot of reading about this, there doesn't seem to be an exact answer yet.
I don't have any noticeable amount of oil in my intake tract, so I can rule that out. However, I have been having trouble with the buildup. My stock motor setup had next to none... built a motor, put in id1000's, different pump, lines etc. Now I'm having trouble.
I have been running the Lucas Ethanol injector cleaner lately and it appears to have helped a bunch. I'm still getting a little, but it's not nearly as bad. It was covering the end of the injector completely.. now there is just a bit around the outside of the injector (shouldn't be effecting the spray pattern now). (Fill at the same station) More time will tell, but it seems better!
Anyone else tried this additive or any others? results?