1987 Ford Bronco stalling

Hey I have a 1987 for bronco and when I bought it it ran fine. The engine had been rebuilt at 100000 miles and now it has 197000. I haven't been using it for about three months but I have been starting it every week to make sure it still ran. When I started it today it started and ran fine for about 3 min then it stalled. The engine would turn over but it wouldn't start. I waited an hour and tried again and it started fine and ran for about 3 min then stalled again what could be the problem? I just put a new tank of gas in it and a new fuel pump and a new fuel filter. Please help.