hey there, nice looking set up,
I guess you have gone over the basics,
check for injection pulse by plugging a noid (or a led test light) light in to the injector wiriing plug, if there is injection pulse that suggests that the cas is sending a signal to the ecu and that a signal is getting out to the injectors,
I know that you said it was running and slowly got worse, but at least it might give you a direction to go if you have got injection pulse, you can then look at coils or plugs
good luck and let us know how you go..