What ever it is, is following your changes, what has stayed the same, that's where to look, I could give you at least a dozen things to ck, but at this point, I don't have much to go on, and 1 gpm of fuel is a bit hi, 1/2 - 3/4 gpm is plenty, hope you aren't using a regulator, they won't be consistant at low rates, even a clamp on your fuel hose will work better than a regulator. Bob