VERY high shifting

[Limited Ex]

Just within the past two days, my transmission has been shifting extremely high in the RPMs. Its an automatic, and does not shift out of 1st until 4000 RPMs, then before the needle drops past 3000, it shifts into 2nd and then into 3rd. I checked the fluid level and there is plenty in there, and I tried resetting the computer as well, no go there either. Any ideas?

 

[RTStork]

First, I would try a ATF flush and fill, and change the filter too. Maybe some other guys will respond with some ideas.