Buly,
 I have an idea for you. Everything was working fine until the snubber mod right? I had a thought for you. What if you had the wrong impedence injectors, from the begining? It might be possible for the system to operate one but then not when the controller internals were changed. It might have caused problems with the controller in the future but you don't have a great deal of run time so far, so maybe there is a more fundimental problem that is stopping you. Everyone has run through the littany of probable MINOR problems, perhaps it's more basic. You are not a inept guy so I have trouble believeing that you messed up the wiring. Your work is better than that. Don't despair you WILL find the problem, and you'll know that the other systems are bulletproof!
 I had a fundimental problem like this bite me once and it is frustrating. My problem was caused durring the installation of a new electronic ignition on a older Kawasaki Z1 900. I installed the unit bread board style with the box sitting on the seat and all the leads jumpered to be sure the thing would work. Ran perfectly. Installed the unit under the side cover, went to start it and no joy. Turns out I had installed it on the battery box, which on that older bike was rubber mounted! I had even scrapped the paint off the spot under the mount ear for a good ground!(Took me longer to find than I would like to admit) ran 1 wire direct to the battery ground and never had another problem. My suggestion is if the impedence suggestion is wrong consider this. Take everything off. Start over like it was a fresh install. I know this will take some time, but you are likely to find the problem partly through the removal anyway. It won't really take any longer than a bunch of failed troubleshooting anyway. I often used this method when a problem was really vexing. You might have wear through a wire bundle or a crack at a mount or under a ziptie. Good luck.
Bill Jepson