After searching everywhere to try and figure out the source of my problem, I think I have found it and will share it here.

The problem was that my 93 maxima would occassionally develop an engine miss, like it was running on 5 cylinders. This would come and go mysteriously, sometimes for minutes, sometimes for days, summer or winter. I suspected it was fuel related, since I maintain the engine pretty well, new electrics every year or so, filters etc. Anyway, when the engine chug-a-chug would start I'd feed it some Chevron injector cleaner. Usually after a couple of tankfulls the problem would go away again. Sometimes I'd also throw in some dry gas, just in case there was some water in the fuel. Then the problem would vanish as mysteriously as it came, with nothing to really logically link it to. Like any typical gearhead, this bothered me no end, the seeming randomness of the problem was frustrating.

This time the problem occurred a couple of weeks ago it seemed more severe, like I only had 4 of 6 cylinders. So i went through the routine, but bought some "Iso" dry gas instead of the regular stuff I'd been using. This is supposed to absorb 4X more water than the old regular dry gas. Well I'll be danged, this immediately cleared up the problem and the car's been running like a top since, very smooth. I was always suspicious that it really wasn't dirty injectors, I mean how fast can these suckers get dirty? Not every 6 months! So, if you have the chugging problem or just as a matter of maintenance, just feed it some Iso dry gas every 6 months of so. Really did the trick for me!