I think the show you're looking for was called "Cover Up". It had
John Eric Hexum (the actor who shot himself with a blank pistol).
It most definitely wasn't Knight Rider.. and unless Fabio has
killed himself recently (we can all hope) it wasnt' Acapulco Heat
either. Cover up (if I've got the name of the show right) ran in
the early/mid 80's, and ended kinda quickly.. the guy they got to
follow up Hexum was an awful actor.
In case you're not sure who Hexum was, he also played the Pirate
time traveller in "The Voyagers" (I think)..where he had the side
kick, and they'd go through time fixing things (kind of a predecessor
to Quantum Leap, except that instead of Al with a palmtop terminal,
they had a very ambiguous stop-watch type thing called "the omni").
Anyways, hope I cleared something up (and sent this to the right
addy).
John