Ok guys, here is some additional information. It appears this car was originally sold in the USA in some state that required a crap load of "smog" related stuff. Like California.
. Which means there is a gazillion vacuum lines, all connected to various valves etc, which any one of them may be causing this. However, the original owner of this vehicle was a Toyota mechanic, who owned, and maintained this car diligently. When I purchased this car from him, he had just replaced all the vacuum lines, the water pump, alternator and a half dozen other things. So I know this engine was maintained by a Toyota expert. But here is the deal.
I just went out and removed the air cleaner, plugged the two main vacuum lines to the air cleaner, and started the engine. I starts like a dream, and runs excellent. At first cold start, it idles perfectly. As it was warming up, I visually inspected all the vacuum lines as well as can be expected and found nothing amiss. As the engine was warming up, the "smog pump" was sucking air from the front hose, and pumping air out the rear hose. Just as the choke fully opened, I heard what "sounded" like a "valve" shut off, and the smog pump stopped pumping and sucking air. At the same moment, the engine started to slow down, until it almost stopped, at which point I opened the throttle and gave it some gas. As usual, the engine revved up, and slowly comes back to idle but continues dying. If I barely move the the throttle, it rev's up, but again comes back to idle and dies.
It just seems like there is some component connected to some vacuum line that is malfunctioning. I don't think it's even the carburator causing this. But there are so many components in this system, I don't have a clue what all of them do, or which one may be causing this. So, anyway, that's what's happening. I now live in Michigan whiich doesn't require "smog" equipment, and wish I could just remove all of it. But..given I don't have the money to replace the carb with a Webber..I just need to solve this. Thanks for any feedback.