Whats wrong with the 86 bronco mystery?

I just bought an 86 bronco 2 2.9l 4wd, when I first start it it runs fine but when the motor warms up it sputters doesnt seem like its firing looses power when I turn it off and restart it its fine for a few miles then it goes crazy again I replaced the throttle sensor ,the idle air control sensor, still not fixed I've got a few suggestions but cant afford to due all of them one suggestion was replce the oxygen sensor, one was replace the fuel pressure regulater, and one was to replace the electronic control module, does anyone know anything about why these 86 broncos do this I've looked at a couple of forums on the subjest and found a few people with the same year bronc and the exact same problem