The sunroof on my 91 940gle wagon was stuck all the way open when I bought it, the previous owner tried fixing it but could not, the motor was out and hanging loose. I took it to a Volvo repair shop, they said the reason is was not closing was because the leading edge of the sunroof headliner had come loose and was stuck, they pulled it loose and charged me $50. They said they did not try opening it again for fear of it getting stuck again. So when I got it I tried opening it, the vent position worked fine, but when I tried to open it all the way it only went about 2/3 of the way back. Also when closing it, either from the vent position or all the way open, it does not stop after the cycle, it goes from all the way open to closed to vent. Is it supposed to stop at the full closed position before it opens to vent, or stop when closing the vent before it goes to full open.

How do I adjust the roof travel, and can I fix the stopping problem, if there is one.

Thanks