I have recently put in another transmission in my 93 4runner. it is an automatic 4x4 3.0. once i have completed it i test drove it. well the reverse works fine but when i put it in drive i hit the gas and rev it up to about 3000 rpms and it barely moves. but i can shift down to 1 and it goes and then shift up to 2 and then to drive. what could be causing this?

 

Check the shifter linkage.

 

could also be shifter solenoids. thats what it was in my truck with same problem.