Stalling after start & stumble on acceleration

[speedwagen]

RE: 1988 Beretta 2.8 l V-6I'll start by saying, I'd appreciate any info anyone might have on this.I'm going to start at the beginning, in the off chance that there's a detectable pattern and all the signs are interrelated, because this car has a habit of throwing many signs out simultaneously, some of which may be red herrings.Ever since we replaced the engine on my wife's car 11 yrs ago, there's been a small issue regarding the car stalling when started on a warm day. It starts OK, but when you put it in gear it tends to stall. More of a nuisance than anything else. A little rpm to get it out of choke mode and it's OK.Fast forward to last winter. We were driving into town on a cold windy day and 15 min in, the car stumbles and sounds like it's running on 1 cyl then stalls. Couldn't restart. Waited a few mins then - halelujah - it lives!I had to go easy on the throttle cause it was running rough and would stumble if I didn't. We stopped at an auto shop and the consensus was iced-up fuel line. Put some alcohol in the fuel tank and that seemed to help eventually. Unfortunately, the problem reappeared for a few days on starting, as in, it would keep stalling in gear, similar to what happens on warm days, only worse. A little alcohol tended to resolve. The problem continued until it wasn't so cold out. At this point, I made up my mind to drop the tank to see what's in there, but I resigned myself to wait til summer.In the meantime, I started to notice the car would sometimes stumble on acceleration. I also started to notice that it was more prevalent on low fuel. That's what I mean about the red herrings and curve balls etc. That made me think that we might also have a clogged filter.Fast forward to present. Took a trip to Blairmore. My plan was to have just enough fuel to get back home so that the tank was close to empty to facilitate the R&R. It was torrential rain, but otherwise no problems whatsoever until we stopped in Ft. Mac ~20min from home with 2 bars on the guage. Did some shopping, started OK til we got to the hwy intersection and it stalled. Impossible to get going without stalling; couldn't even get it to rev. Must have tried 30 times. I finally got going by coaxing some rpm and putting it in gear with the revs up; it stumbled like hell, but it finally took. Once in the groove, no problems. Got home on the last bar; according to my calculations, there should have been ~20 oz of usable fuel left in the tank.Yesterday I dropped the tank and emptied the contents in a white pan; to my amazement, no dirt, no crud, no rust, however, there was ~¼ c of geen liquid at the bottom. At first I thought coolant, but it wasn't fluorescing nor oily, but it felt like water, ergo, it must be water. How did ¼ c of green water get in the tank? I have no idea. There was ,however, > 1 gal of clean fuel; by looking at the the inside of the tank, that fuel is always below the pump sock, which also tells me that that green water would never make it to the pump. Furthermore, we could never get water in the fuel lines unless there was at least a gallon of water in order for it to reach the pump unless the water would come from somewhere else, where and how, I wouldn't know.So now I have no idea what the problem is, because with the dregs being so clean, even the fuel filter isn't likely dirty. I read a post by yoroi from 5 yrs ago regarding him replacing the fuel pump 3 times only to find that the problem was with the pulsator, but it seems that his problem was immediate and consistent. If our pulsator is the culprit, why would it only act up/leak during the circumstances described above? Anybody? Thx.