1995 buick riviera supercharger 3.8l wont start

hello I have a 1995 buick Riviera 3.8l supercharger
that I purchased a year ago for the past few months
the car has been stalling while driving in low speeds
or idle and at the same time my alternator belt has
ripped twice for a reason unknown  but the last the
car has been stalling alot frequently my mechanic
replaced the crankshaft sensor and 4 hours later the
car stalled 4 times before it wouldn't start anymore
my mechanic says their is crank their is a spark theri
fuel in the engine he replaced  the crank sensor again
didnt help he replaced cam sensor  crank wiring
harness ignition modulder maf sensor is new. he isnt
able to see a problem why it wont start and the
computer wont give any data even a pc replacement
I read these forms and apparently it's a common
issue in the old school bucks anybody knows
anything?