uploading your simulation files would be helpful.
By now i don't have those original files in this computer, but i will try to explain with more detail.
I assemble a four bar mechanism with counterweights (as shown in the next figure)
then I added a motor with constant velocity (500 RPM) at point A. This bar shoud give an entire turn on 0.12s. Then I make the motion analysis and I obtained the torque of the motor and exported it to a .csv file.
Then I generated a new motion analysis where I introduced a torque on the same joint where the motor was. I introduced the torque through data points (the one obtained from the first simulation). I was expecting to obtain the same movement like in the first simulation but it was not the same, not even the velocity of the red bar was 500 RPM, so I don't understand what is happening.
I hope this explanation will help... thank you very much in advance =)