The throttle position switch has a series of make-and-break contacts when you step on the throttle that act as a sort of accelerator pump, telling the computer to call for a little extra injector duration. Also, when the switch contacts get dirty, you will typically get a momentary cutting-out of the engine when cruising at a light to medium throttle position. You can pry open the cover on the switch to clean the contacts, but lay a rag or something under it when you open it as there are some little rubber grommets in each of the 4 corners of the cover that may fall out. Some people have reported that clening the printed contacts with an ink eraser works good. I've used alcohol and Q-tips. I've also VERY CAREFULLY tweaked the little contact fingers so that they track down a fresh path when you rotate the throttle.

How did you verify the trigger points are operating properly? They can look perfectly fine when you look at them, but what happens is that the fiber cam followers wear down and then they don't open good enough.