Sun roof trouble

I have a 1999 sunfire 2.2 I am having trouble with the sunroof. It works correctly ever now and then usually when the interior temp is high (ie. when it is in the sun all day). It sometimes opens to the vent stage, sometimes opens 4 - 5 inches, does not close all the way. I have tried greasing the track on the occasions when I do manage to get it open. I have visually looked at the track, rubber gaskets to see if anything looks out of order. I am not sure where the window motor is located or how to access it. I have not had much luck at finding any answers on the web or in the chiltons sunfire repair manual ( actually it does not even mention sunroofs) even on here there are no threads under sunroofs.
If anyone has any suggestions i would really appreciate some suggestions....
Thanks..:)

To get to the sunroof motor you need to drop the headliner. The motor and the drive mechanism are just forward of the sunroof.