Jeep sputtering

Drives fine then for no reason will act like it is running out of gas, and get no response from the gas pedal unless I flor it then it will go, if I push in the clutch and give gas the rpms will go normal with the pedal, this has been happening intermittently but now it is acting up more frequent and does not want to idle normal it will spike up and down and has stalled once, I just bought it and put a new filter on to see if that was the problem but it did not help also the oring for the pump was leaking gas from the tank I fixed that too also the oil pressure fluxuates from 30 to around 80 at times normal 40 to 60