shaking?

[Fast95Bird]

my bird just started to shake out of no where, especially in Drive. Neutral and Park don't seem to help much either. it didnt do this prior to driving it 30 min earlier. Possibility of a fuel pump failure, but i replaced that less than 6 mos ago. Tank is full enough and its never done this before. Put injector cleaner in it two weeks ago as well. I guess it could be the spark plugs, maybe one came loose or is totally busted but I haven't checked it all out yet (notice the time) its late and dark here..just wondering what to look for in the morning...thanks guys..

[BowTieBob]

Check for a vacuum leak.