Check fuel pressure and check the filter also when it dies check for spark if you have no fuel pressure it is either a relat which you can jump test or it is the pump if you have no spark it is either the distributor or the ignition module

Does the truck fail to start for a few minutes, and then suddenly start working fine? When it shuts down does it act the same as if you had turned the key switch off? Pay attention when trying to restart the truck, if it tries to fire when you release the key from "start", but you get nothing while actively cranking , the problem is likely the pickup coil inside of the distributor. The pickup coil is the device that tells the ignition coil to collapse its electrical field that when collapsed sends electrical current to the distributor and ultimately the spark plugs. When the pick up coil goes bad, the ignition coil does not get the signal and only collapses the field when you quit trying to start the engine, the result is a sort of false start. It is also good to note that most people get rid of these trucks for just this very reason after replacing hundreds of dollars in parts over months they give up and will sell them cheap. I almost did myself, I bought an old Ford F150 from a friend who got tired of the truck quitting on him whenever he went anywhere. I replaced just about everything and was getting frustrated when an old Ford mechanic told me to check the pick up coil.You can test the resistance in the pickup coil to see if it is good. I believe that 600 to 900 ohms is acceptable. Double check this as I may have misremembered the numbers. With a little help you can replace the pick up coil in a few minutes , if you are very careful it can be done without removing the distributor.I bought a replacement part for around $15 or $20 at Autozone.

DID YOU TRY A NEW COIL BUCAUSE MINE DID IT TO.