I have a 2003 v6 manual transmission, and it seems that when I shift into first from a dead stop it hesitates/doesn't feel like it's getting enough power. This makes my takeoff a little jerky and makes it look like I don't know how to drive stick. It's most noticeable in first but I can tell it happens a little bit in second as well. The problem seems worse when I have the AC running. Any idea what the problem could be? Also, it seems to get worse when I drive for longer periods of time.