So I just bought my daughter a 2000 grand Cherokee limited with the 4.0 and it’s the quadratrac.its slow to shift if I don’t let it warm up for a few minutes but after that it shifts perfect and doesn’t slip at all,any thoughts TPS?
Maybe just dirty filter and needs fluid to get warm and thin

 

That transmission is probably tired and needs to warm up since the o-rings are getting hard and need to soften. Also, warm it up in neutral because the pump doesn't pressurize the converter in park. It doesn't need more than a minute or 2 to get the fluid moving properly, but when cold, it will tend to not shift. In extreme cases, it may set a code for governor pressure low. When it's near zero, I'll let it warm up until the temp gauge starts to move. Mine had 252K miles on it before I replaced it. That's a lot for a 42re without problems.

 

BTW, That's a WJ, not a ZJ. If you want the know more about them, go to wjjeeps.com