Transmission swap just done and it seems to slip from 1st to 2nd

Hi i just did a transmission swap on my 1999 tacoma automatic 4x4 and it seems to slip from starting off to 2nd and it works fine after that as far as i can tell i have not drove it much. We made sure everything was right on the swap its all hooked up and everything. only thing is alot of the fuild spelt out the tourqconveter when we was installing it but that shouldnt matter should it? cause i filled it back up with fuild when we got done.

Is there a certin amount of time u got to let the truck run after doing a swap or is there something wrong

also i forgot to hook up that little Vac line from the tranny to the transfercase could that cause this?

 

what was the tranny out of?

ON my Dad's old Dakota a vac line was missed and he had all sorts of issues with it, well issues above it being a Dodge

 

it came out of another 1999 tacoma 4x4

 

I put some lucas stop slip in it and as well as it seems when i take off if i push the gas then let off it then push it again it dosent slip. only when i push it and try to take off dose it slip

 

Recheck the fluid? i drove it some and checked it last night it was pretty full. i haven't checked it seance i added stop slip

no didn't change the filter i can do that if u think it would help