I haven't installed new filters in about a year. Since four cylinders are firing I don't think thats it.

I should have put the valve adjusment in the sequence of evens. It was most recent actually. I did it after the new injectors didn't fix the problem, hoping that the valve adjustment would. Certainly possible that I botched it up. I'll look at the valve adjustment on the first cylinder.

If that doesn't work, I'll get some old injector lines and see how the nozzel is spraying. Since we're on a roll here, if these methods DON'T WORK, what next?

Is the fact that this problem originally happened over night a good thing or a bad thing?