Hesitation
 

I've got an 83 non-turbo with 210k miles. Recently I've been having a problem with it hesitating under acceleration when it's warmed up. And when it's cold and I give it gas it wants to try and stall and backfire. I have no problems starting it though. Also the whole car will surge in gear when it drops below 2000 rpm. I've replaced the distributor twice cause the 1st one the module was bad. New fuel filter and pressure regulator. I've checked the pressure and it's fine. Also checked to see if the oxygen sensor was bad by looking at the inspection light and it checks out. So I'm really at a lost. Please help!

Z