How can you tell if your fuel pump is going bad on your 1992 Pontiac Le Mans?

Electric? or Mechanical? For the cost of the pump, if I was in doubt, I'd simply replace it. If that doesn't fix your problem, then you have a spare fuel pump. If that's more money than you want to spend, and it's an electric pump, remove the "out" side fitting, and have someone turn the key on. Should be a strong stream of gas. If it's mechanical, unbolt it, work the lever with your hand. A shot pump will have little or no resistance.