sluggish initial acceleration

I have an automatic 1993 Camry V6 (135K) and this car is nothing but trouble and is killing me in the pocketbook.  Right now, I'm having an issue with sluggish initial acceleration in D gear.  The car makes a sound like it's trying to get into gear when I first step on the gas pedal.  I've dropped the pan on the transmission and have put in a new A/T filter and replaced the fluid.  And yet, the car is STILL sluggish.  All the other gears (R, L, 2) work just fine.  And it drives smoothly in highway speeds, no sluggish sounds or anything else. 
 
Any help or suggestions would help and be really appreciated. 
 
I also have an automatic 1993 Camry LE (132K) and that car has been a bitch to maintain too.  We once had issues with the R gear not working from time-to-time and we dropped the pan and replaced the A/T filter and replaced the fluid on it and it running fine (knock on wood). 
 
So please help if you can.