steiner_5000

I recently got an 86 GXL for a project car to play with. It sat for about 3 years until I got it. I can start it up and it will run for about 20-30 secs then wil putt and die. It'll do this about 2-3 times then it wont start at all. I put new spark plugs, fuel filter, fuel pump and cleaned out the tank. any suggestions??thx