727

Hi, my 727 in my Barracuda doesn't want to move if It hasn't been used for a few days. I usually pop it into neutral and let the front pump run for a sec and it takes right off. It will operate fine for the rest of the day. It shifts great and has no slippage in any gear. It was rebuilt about 1,000 miles ago (last year) and has been doing this since. I have a feeling the torque converter is draining back but I'm not sure. Any Ideas???