I have a 86 targa,when the door is open the window goes up and down perfect,but when the door is shut it goes up very slowly and catches and stops.Could it be the runner the window sits in or the motor..IT has had new seals a while ago but they are not getting in the way
It's a mechanical issue IMHO. When the door is open it works perfectly if I understand it.
I would gently loosen the runners and then shut the door. Operate the window a few times to position the runners correctly and then carefully open the door and nip them up again.