Engine stumbles when you try to accelerate.....help?

my 95 Subaru has the 1.8L and an issue. when you push down the gas pedal quickly, even in neutral ( its a 5 spd.), the engine sounds like its misfiring and loses power. I've done a flow rate test for the fuel pump through the filter, about 3oz when you turn the key. When its running, I unplugged one injector at a time and when it misfired it was on cylinder 3, but after switching injectors with number 1, it still does it on 3. New plugs, wires, and coil. I have no friggin clue any more. I need some HELP! Thanks guys...