Starving for fuel, misses, backfires, stalls

Seems when the manifold vacuum is high, it surges, stumbles, backfires almost as if the timing was completely hosed or it is severely leaning out. This seems happen about 5 or so minutes after starting just before 'service engine soon' lamp pops on. I replaced the O2 - error code and the MAP - codes 34 and 35 which is low and high MAP voltage. With a new MAP, the problem got worse. In park looking at the FBI, the spray looks fine at any rpm (one is a little 'drippy' and not symmetrical. it and needs to be changed but is functional). It acts as if it is starving for fuel. it's very similar to to 'chevrolet-astro-1987-chevy-astro-starts-then-dies' thread. It has no problem starting. and doesn't seem to be missing at all. The dist cap, rotor, plugs all are new.

There was a earlier thread about a built-in software booby trap turning everything off after a certain time. I cannot accept this. There would be too many lawsuits floating around for this to be real.

iATN has a blog that exactly describes the problem but I cannot get at the answer because I am not an Automotive Service Professional and appealing to them is as useful as teats on a bull.

http://www.iatn.net/techhelp/69/14362/1987-chevrolet-ast

I am completely baffled by this one. I haven't checked fuel pressure other than loosening the filter nut and watching about a 10 psi leak spray. Should pressure be checked at the filter or the FBI. Ideally, they should be the same. The filter is new. There is an internal pressure regulator within the throttle body I believe, but I'm not sure. Is there any way to check this?

if ya give me a handle on it, it's worth a donation for sure, I'm pulling my hair out, but on the flip side I've paid for information in advance before and have usually been scammed with total indifference. I'm on a fixed income flirting with bankruptcy ... that's why I drive a 1987 Chevy... and can't afford to be scammed again.