You had two different problems going on at the same time. Yes, your IC pump was bad, that was why you would get intermittent power while cruising. The shaking, rough idle is usually a bad crank shaft position sensor. They don't always go bad all at once, but will give a warning from time to time. Under $50, and it will need replaced sometime...so I would go there next and see if it helps. Cam shaft sensors can go bad as well, but not usually the culprit 90% of the time...