Here's the scenario:
98 V70R 70K miles - has been running fine, my wife was driving it, gas light came, went to the gas station and fills up. Very soon thereafter car begins running poorly, stumbling, erratic idle and then stalling. The station was a no-name station, it has been raining for weeks here in NJ, so I'm thinking bad gas. I buy a couple of bottles of dry gas and put it in. I was able to get it home, but it did stall and stumble a couple of times.

I let the car sit overnight, go out and start it, it fires up each time without incident, but is having trouble holding idle, sputters, then stalls. But eventually it catches. When the engine is running it sounds fine, then it will just faulter, sputter and almost die and either catch itself or stall. Again I'm thinking that there is water or something in the lines so I am increasing the revs and holding it at betw. 3K and 4K RPM. It sputters a touch here and there but seemed to be running fine. I'd let it drop back down to idle and then repeat. This seemed to be working, the engine sounded fine, but then it started stumbling again. Each time it stalled it would fire back up on the first crank as it always does.

Then all of a sudden it starts throwing a crap-load of smoke out the exhaust. Nothing is coming out of the engine, no leaks, no smoke no nothing. But the tailpipe is smoking badly. The smoke was whiteish - I was thinking I may have blown the head gasket, but its not as white as I've seen when that happens (although it has never happened directly to me). The smoke smells very sulfury - like rotten eggs. I stopped the engine, cursed the car, then threw caution to the wind and started it again. It smoked, but not nearly as bad and again rotten eggs.

By way of background the air pump went on it a couple of months ago causing the Check Engine light to come on and stay on, I was planning on getting that taken care of as the colder weather set in. Unfortunately I don't have anything to pull the codes.

Any ideas or guesses? Thanks!

-Dave