[HoodStrype]

If you haven't changed anything I'm starting to wonder. It sounds like you're not getting enough fuel under load. There is a place for a flat head screwdriver on the piece that holds the vacuum line on mine, it may not be stock. But it should not be just now having fuel problems if you haven't changed anything...
Now the vacuum just needs a good source, I would change that line or check it for a leak. When you pull it off the fpr does it stick to your finger, or slightly pull, or not at all? It should be noticable I think. My friend has very little vacuum and upped his fp. It was jerking a little and now it is perfect. As I was saying that was the problem on my car and we just fixed it. It was hesitating badly under alot of load... like 3rd and 4th gear at 1500 to 2200 rpm. Somtimes it took 5 or ten minutes to start, sometimes immediately. Mostly going up hills at low rpm.