I just bought a 1978 f250 6.6 liter 4wd 4 speed, I drove it home and it did fine, but the next day I went to crank it and it will crank but won't idle, I pat the gas to try to keep it running but that only works for about 10 seconds, does anybody have any suggestions on what could possibly be wrong with it?

 

If you hold your foot on the gas to keep it running, does it idle once it warms up? Could just be a poorly adjusted choke.