I just recently got a 1987 F150, 4.9 auto. It had been sitting for months before I got it. It jump started fine, and the battery charged back up well. It wants to die often for no apparent reason. After sitting for a while, it will restart. It doesn't seem to be just when returning to idle, or under load, just randomly, hot or cold. I put some injector cleaner in the tank, but haven't driven it enough to see if there is any improvement. It looks like the plugs, wires, cap, and even coil have been replaced recently. Any common causes to check out?

 

Fuel Pump?? sounds like its not getting any fuel. might check that out.

if its been sitting for awhile changle all the fluids and filters and do the seafoam treatment its in the how to section of the forum