Chevy blazer 2000

Current Problem: Won't start. The problem started out as hard to start, running rough but idle good. When you try to accelrate it would jump and buck. Sometimes bog down like it was not getting fuel. But other times it would run good for a short time. Also when it did start it will idle good but as soon as you tap the accelarator the engine would die with out delay. Have already replaced..........1. fuel filter 2. fuel pump 3. distrubuter cap and rotor 4. Coil wire 5. spark plugs.. Have checked for... 1. spark to plug 2. possible play, loose or broken timming chain. When you turn engine by hand rotor moves back and forth with no lag time. The computer is getting voltage because check engine light comes on when you turn key on. Also removed the EGR valve to check for carbon built up and if valve was free, no obvious problem there. Tried..... Putting gas down the throttle body just in cases it might not be getting gas thru the injectors and tried to start the engine but it still would not fired, we got a one time flutter but no run. We have rolled the engine so much we were getting a heavy gas smell so we opend the throttle body all the way to try to clear any possible flodding problem still no fire. Need help Thanks Robertintx