Humboldtrx7

Ive got a 88 gxl and i was driving the other day kinda gettin on it with my friend in his 240sx. And just a little bit after that it started running like crap kinda like it was outta gas. I pulled over sat for a minute then went an put gas in.it (even tho i had a quarter tank) and when i started it up and drove away it was ok for a few blocks then it started to kinda cut out when i push the throttle even remotley hard. Now this doesnt really happen when its cold but once its warmed up it gets a lower idle than usuall and if i push the throttle hard from a stop itll drop rpms and die. but if im already goin itll just bog down and then go?? Any ideas at all whats wrong??? I just got this car so im new to rotarys and rx7s in general. Im being told it could be the fuel filter? also been told it could be a dirty MAF?? Its either not gettin enough gas or air?? Please help!!