I do this every time I acquire a new vehicle and its always a good starting point.
You can't always go by what the previous owner says they have done, or when.
Consider doing the following:
Oil Change (AC Delco filter)
Spark plugs (AC Delco)
Plug Wires (Either Belkin available at NAPA or Dealer wires)
Change the Oil in the Super Charger (Get the SC oil from the dealer)
Use the proper Gas for this car 91 Octane or higher aleast put in $20
Start with what I listed above and go from there.
Also a good idea as mentioned earlier to get your hands on a scan tool and do some tests.
If you have no boost as you mentioned then something is wrong.
92 Bonneville SSEi - Stock - Remaining repairs needed due to neglect by previous owner - ABS/Trac, AC.
Mods so far: Maganflow High flow Cat, Rebuilt */C
Future Mods: Interior swap for Leath, High Output Altenator, Crazy system, Climate Control swap & Custom Exhaust/Intake.
98 Dodge Stratus - Wifes Daily Driver
92 Dodge Shadow - My Winter Beater