Ya I know its not a mustang, but I'm not familiar with any Honda forums and my brothers on a little bit of a time crunch.

Its a 1995 Accord 2.2 VTec the Trans is a 96 Automatic. Trans was put in about 2 months ago. Said he hasn't noticed any issues since the install. He drove 8hrs about 500 miles trip to my house for thanksgiving and said he didn't have a issue. He got a few miles from the house and had to make a uturn and then he noticed a slight hick up. RPM's went up but not transferred to wheels. He said it was just for a moment then power returned. Weather at the time was 20-35 degrees with sleet.

Next day we drove his car about 30 miles to walmart outside temp was 20-35 degrees once again and ran fine. Spent about 2hrs in walmart got 10 minutes down the road and lost power again. We tried every gear to get it to get power. At some points it would get power for literally a second at high RPM's and then loose it.

We got it towed to my house temp around 15-25 at this point. Unhooked it from the truck and the car drove perfectly fine. Shifted in every gear fine now powerloss nothing. Until the car warmed back up. Seems to work great after it has sat turned off for a few minutes. But once it warms up no power to the wheels.

We'd appreciate any help or insight on this thank you.

Checked the fluid and topped it off.
Not grinding, knocking, nothing. sounds perfectly healthy when running.

 

Sounds like a fluid issue.

Check the service/owners manual and make sure the correct fluid was put into the tranny, as well as the correct amount. Automatic tranny’s are fickle about their fluids. Too little or too much can cause the problem your describing. They are also designed for a specific type of fluid. I know Honda makes their own tranny fluid, but I don’t know if it is the same as regular tranny fluid, or if it is ATF or something else. Double check.