will it run at wide open throttle?? if so, then mash on the gas up to rev limiter (or even more if you wish, i won't tell...). you may have dislodged a piece of carbon into the egr system from the long cruise. this sort of thing can happen from time to time. i suggest a top engine cleaning, or some sort of fuel injection service (no, not the stp mechanic in a can pour it in the gastank and everything will be fine stuff). i suggest a 'motor-vac' by snap on. there are several service centers that use these, or the b&g units, either one will give you a far better service than the bottles of mystery oil on the shelves in the stores.
if it doesn't run at wide open throttle, then you may have other issues, but i think it will be carbon. you chould also have the throttle plate cleaned as well.
hope this helps.