Years ago I had the same issue in my '85. Seemed fine if I never took my foot off the gas. Once I did, it just quit. Not all the time, but intermittantly. I would do the fuel pump. My pump turned out to be a tiny little universal thing the previous owner had put in. Got a good used big-boy Toyota pump and had no issues since. Simple to replace, but you have to drop the tank. I suggest running it out first. Keep a gallon on you, and once it start bucking, add a little fuel to get it home.

85 4Runner - With NEW Marlin 4.7 Gears!! It's a whole new beast!