would low vacuum cause a TBI car (89) to run excessively rich, when I say low it's around 12 inches of vacuum, also when I come to a stop my brakes barely stop the car and become very hard to push.

what could cause this I see no vacuum leaks anywhere, maybe this explains my car failing smog bad

 

Low vacuum would run on the lean side. When a vacuum leak occurs, air is getting drawin in from a location other than what is metered by the throttle body. Under normal conditions, you increase air volume, you increase fuel. It's a ratio set by the computer. Any air beyond this is unaccounted for and the amount of fuel is not increased. You run lean.

Not certain about the rest. Perhaps you could try in the TBI board. Shifty and co. really know their stuff over there.