1989 Pontiac Firebird Trans Am?

[The Seeker]

I've got a 1989 Pontiac Firebird Trans Am. It has been sitting for a while and I recently took it out for a short drive because I noticed when I started it up the engine had a slight miss. When I came back from the drive, I shut it off and tried to start it again, but it wouldn't. After priming it, it starts and runs with the miss, but it won't start without priming.

Do you know what the possible issues could be?

Thanks a lot for any help!

 

[melsg5]

First question would be what do you mean by "sitting for a while", 6 months? 1 month? etc. If a long time the gas could have skunked. Where was it sitting? Could mice have gotten into the engine wiring?