Thanks,
pjwest03, for the suggestions. Yes, I find an ultra-sonic cleaner is essential equipment for cleaning my injectors. I used a 1qt one to clean my 6.2L injectors for years. I now have a 2qt one for the large injectors for the deuce. The 2 stuborn injectors have been ultra-sonically cleaned for 48 hours in stale gasoline, which has alcohol in it at 30%.
In the past I have used lacquer thinner to remove the gum that comes with burning WVO. It works great. I have also found that pure gum turpentine also works great. I have also found that MEK works great for this as well.
This weekend I plan to use fresh gasoline with alcohol in it. Hopefully it will solve the problem.
Also, the manual suggests probing the hole/s in the injector tip with a .025 wire. I happened to have a tip cleaner for my wire feed welder. I found its smallest wire (.015) works quite well, but I cannot seem to get a larger wire in the holes, so i am hopeful that .015 will work fine.