2 days ago the engine started to run rough. when at 30 -50 mph seems ok. at a stop it has a miss and runs rough.. Now at the same time this happened my transmition seems to be slipping.. If I excellerate at say 2500 rpms it shifts almost OK but a little slow.. I tried to excellerate and went to 4000 rpms but my speed increase is slow maybe half of what it should have be..Any ideas , it seems strange that 2 problems at the same time? (2001 s-80 with the 2.9)

Thanks so much : Bill