94 Altima: While accelerating, the vehicle hesitates and even jerks

Could be your mass air flow sensor. That unit can often be cleaned with carborator cleaner.

It could also be a vacuum leak. Carefully inspect all vacuum lines and make sure they are not pinched, are properly hooked up properly and not have leaks in them.

So would this problem only occur when the car is working at a higher temp than normal? This started last summer no one could diagnose the issue, everyone said it must be the transmission? Then of course the transmission specialist could not reproduce the problem. When it cooled off for winter outside the problem not one time occurred. We now are experiencing a heat wave in the south and it is happening every time I use the car. It is so embarrassing, there are usually people backed up behind me! I also bought the fuel treatment that was STP combination treatment for the entire fuel system including the corroborator. Whatcha think?

issue,

transmission

We should first define what you mean by hesitation and I am assuming your car is an Automatic:

When you press the gas pedal, does the engine rev up normally but the car not move, then? If so, does it then slowly start moving or all of the sudden slam into gear and move?

If the engine revs ok but the car does not move, it could be your transmission or fluid. Just making sure, but you have your transmission fluid at the right level, right? I've seen it where grit gets into the fluid and causes this sort of behavior. You could get your transmission fluid changed, which is inexpensive option to see if that fixes the issue.

Its the A/C... I have a 2000 altima and it does the same thing. While driving you feel a hitch or hear a click when it happens? I haven't been able to fix it, but its most noticable on the highway w/ the A/C on...