My truck sat unused for a month, now it's missing during acceleration, any ideas?

[MikeS]

Vancouver got hit by a bad snowstorm last December, and today was the first day I've driven my truck since. It ran fine for the first half hour, then began to miss during low RPM acceleration. It doesn't stall, but it accelerates pretty choppy until I hit around 3000 RPM. Once I hit a steady speed or sit idle, everything seems fine. I tried some fuel additive that is supposed to rid your fuel system of water, but it didn't do much. The only other thing I've done so far is top up the tank with fresh gas.

The engine in question is a VORTEC V6, carbureted, with about 60,000 Km on it. Any help is welcomed...

[tampabaylive]

Ignition coil could be going out.... Plug wire could be arcing, I would wait till nighttime, then open the hood and look for arcs in the dark, if you have a hood light, disable it and park where there is no light... If you see any light happening under your hood while doing this, locate where this is happening and replace whatever item that is arcing...
That would be my first attempt to fix this problem.
If no arcing is evident, I would check the coil...