Ok I thought i fixed my problem, but didnt. My gsr one day started to sputter and then stall out and die. It does this when i just tap the gas or try to start out, sometimes it makes it past the sputter and revs fine in the upper rpms. When i tried to start the engine exhaust shot out of my intake. Checked compression everything is fine, new fuel filter, plugs wires, I checked my timing belt which was changed about 20,000 miles ago and the belt was really loose but valves seemed ok. So I tightened it up and it seem to be running all right, not moving. I pulled out of my driveway and then in going down my road it did the same thing, sputter, lose revs and die. I havent checked it after that, There are no codes, and I have no major engine work. Tensioner broke, new belt, Fuel pump, vacum? Please help