MAP sensor is a common problem with the Speed Density engines like this one. I would check there first. If that checks out, check the fuel pressure. Does this truck have dual tanks?
You know what I do with every older Ford I own? Unplug the IAC and find the idle screw that they say not to tamper with,then get the vehicle to idle on it's own.. Solves every stalling problem that can be mustered up
__________________
"Genuine" ASE certified Mazda, Hyundai, Isuzu Technician
Escort Enthusiast Site
Automotive Electrical Specialist, Tuning Specialist