97 no low end?

I just picked up a stock 97 12v with a raptor100 and it is a auto, it is completely gutless on bottom end until 1800 rpms. AFC stock location. Haven't been able to check plate yet. Acts like it is running a massive single but it is not. No smoke of any color. And when running around town and the converter locks in od it slowly dies. And ideas why and what to check? Thanks for help in advance