White "smoke" just after starting and a bit after maybe condensation. That will quickly stop.
White "smoke" w/ engine at operating is likely Coolant problems.
Intake and/or caskets to crack head etc can make engine to "burn" coolant.
Head issues can "fake" boil over too because cyl have way higher pressure.
Intake has coolant in them and caskets can fail. If morons replace coolant senders/sensors then may have crack the intake when they over torque the part.
⚠️ Warning: Do Not breath white "smoke" or coolant steam anytime!
Ethelyn Glycol can kill you and "smelling Sweet" may not be there to warn you as other fumes can mask that.
Fiero has SS exhaust and replacing it won't help you. Low mile engine is unlikely to have Cat problems unless has "burning" coolant problems.
if let parked for mounts to years, Water Pump can go iffy/bad just for that.
Coolant goes "bad" even w/o engine running and won't protect for "rust."
Even w/o that, parked WP can get rust on shaft and eat the seal when running after. WP Seal isn't 100% "water proof" and tiny bit of "leaking" coolant lubes and anti rust the shaft.
(Other seals to same for axles, crack, and brakes.)
If replacing WP then Flush coolant too.
See my Cave,
Coolant Fill------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)
The Ogre's Fiero Cave