this sounds kinda like how my car acts, not to be a thread jacker. But when im at half tank my throttle starts to cut out and i have to like pump my throttle for it to maintain an idle.. ive had it just die on me driving down the road. Im gonna watch this thread.. maybe itll be of some use to me.
Good luck on fixing it!
Not to further threadjack, but that almost sounds like the TPS right there..