well I would start pulling codes, if you do a search on youtube it shows how you can do this with a paperclip, or you can get an obd1 computer to read the codes. Be aware that while there is an OBD2 harness on the console that it is not active. The v6's used obd2 and they knew the change was coming so rather than redesign the harness they just made the 94 version ready to upgrade when the time came(96).
The reason I asked if it was new to you is that if you compare these cars to many modern sedans(not sports cars), while it is in stock form it only makes 215 hp at the crank and many of the new v6s have that or more. So it might very well not have any issues and you just were expecting more. My only idea to find out if/how much slower it is than when new would be to get a dragy or take it to the track and see what kind of times it can run, but if it is having engine issues this isn't a great idea.
Check the codes, maybe pull a plug or two(it is not hard on these assuming it doesn't have some aftermarket headers) and that can tell you a lot of what is or is not happening.