Acceleration Hesitates

[Matt Cramer]

What kind of mods do you have? Sounds like your tuning is way off in that particular area. It's probably going too rich and not igniting in the cylinders, then the unburned mixture lights off in the exhaust.

It's very rare for a too large fuel pump to cause trouble, unless you are powering it with a wire too small or have a fuel pressure regulator so restrictive that the fuel pressure goes up. And in that case, you'd have the problems show up mostly at very low RPM.