Okay so a couple months ago I noticed that my blazer started to spit and sputter as if it was running out of gas when it clearly wasn't so I didn't think much of it for the time being because it went away then it came back and it was worse so I replaced the cap and rotor plugs wires and the fuel filter still it was bumping and jerking around now it's starting to cut out and when I start it up the idle is rough and when I put it in gear and accelerate it pops and bangs under the hood and won't move with the pedal to the floor it only revs to two grand then after about a minute it will all of a sudden take off I have no idea what the problem would be any suggestions??