4A-GE MK1 Engine car driving rough/ 20 mph/ backfire noise, help!!

4A-GE MK1 Engine, changed, coming, fuel, week, cooling, r134, exhaust, smell, popcorn, burnt, smelt, engine, heard, backfiring, fans, sound, popping, daily, driver, mahalo, quickly, fixed, throw, thought, driveway, complete, struggle, acceleration, stop, filter, noise, backfire, rough, driving, auto, drove, barely, uphill, feet, feels, drive, test, worse, passing, time, hard

ok. so I have an 89 auto. Once in a while the acceleration would struggle coming off a complete stop, like it was not getting enough fuel so I changed the fuel filter and took it for a test drive, It feels like it got worse. It had a hard time passing 20 mph and 500 feet to my driveway it barely drove 5 mph ( going uphill ) What could it be? I also smelt a burnt popcorn smell coming from the engine. Also, heard a popping sound like an exhaust backfiring. I did get the a/c changed to r134 last