door won't open all the way
 

On my '88GT, all of a sudden my driver's door won't open all the way. It opens about 3 inches and binds up with the front fender.
It just happened today out of the blue.....why?
Is there a way to adjust it or what needs done?
I did notice that the gap between the door(where you enter) and the rear quarter is a little bit larger than the passenger's side.
Please help.

Has to be either
 

the door hinge pins, or the hinges themselves. Also make sure no shims fell out from behind the hinges. If you have to change the pins, or hinges, I suggest removing the fender. Sounds like an ass ache, but it's worth it in the long run!

The hinges will also break the welds between them and the body and cause the same thing, i've had it happen to 2 mustangs i've owned, pain in the @rse. Good luck, i'd inspect the welds just to make sure.

found the problem
 

I figured out what it was. The end of the molding trim on the door was starting to come off which caused it to interfere with the fender. What happened was that it happened one day at work and I wasn't in the mood for it so I forced the door open.
I got home and looked at it to see what was going on and noticed when I forced the door open, I bent the edge of the fender in which was why the door wouldn't open very far.
I took the claw end of a hammer, wrapped it in a rag and stuck it between the door and fender and pulled it out where it belonged.
Problem solved.