Engine jolting and RPM's fluctuating randomly

For the past few days wherever the engine is under load (acceleration, in drive, ect.), The engine will periodically 'jolt' or 'jump'. No sound out noise, just the single bump or two and it gets worse under light acceleration. Under medium to high acceleration I'll either experience a loss in power so together or the engines' rpm will fluctuate randomly about 200 rpm's faster or slower. The symptoms got better after filling up with the good ole 87. I replaced the MAP sensor recently so it could be that but I'm not sure.