I got the same problem and have been dealing with for 9 months intermittently. I have replaced the igniter and ignition coil, clean air filter, new plugs, wires rotor, rotor cap, new distributor housing, and full tank of gas and it still does it. Now it just started to die on me while driving randomly. Do you have a full tank of gas when it hesitates? Some people have bad fuel pumps or the filter came off and the fuel pump can get fuel when the tank is low. I haven't checked timing yet. I still have to buy a timing gun. No CEL, no leaks, no smoking, no oil consumption, etc. Have you replaced the fuel filter? I didn't do it yet because why would it only in 1st or 2nd gear accelerating slowly around 20-25mph? I am stuck so I'm ruling it out by replacing it. Any progress on your situation?

 

I did change the fuel filter.I haven't noticed if it only does it when the tank is low,but i don't beleive that makes a difference.I will check though.And I have checked fuel pressure with a gauge and it does not change,so I kind of ruled out being fuel related.I am stumped myself right now.If I do find the problem or try anything else I will post it.

 

You should read this thread.

 

I would look down the throttle body to make sure its clean.