Trans. Temporarily Stuck In Gear

[rumbold11]

Its a 1994 Ranger 4.0 4x4 Automatic Transmission and whenever i first start going it gets stuck in first. It wont shift up unless i floor it up to about 3900 rpm then it shifts right into 2nd gear. There is no clunk or rattling at all when it does. Shifts just fine. It was working fine the other day. After it shifts the first time everything is back to normal? Any input is greatly appreciated!

 

[BlackBII]

Checked the fluid already I hope?

 

[rumbold11]

yep, im wondering if would be anything to do with the cold, but its only 25 degrees so its not too bad.