I have a similar problem to those discussed above. F-150 300 straight. Runs And starts good in cold weather. Starts in hot but when I run it and shut it down wait, its hard to start.

Was the igniter/pickup/stater replaced in distributor, Not sure if this is it or not but I had a issue with mine stalling out after 15-30 minutes then would not crank back up for 30-45 minutes. Ended up being the pick up igniter module, located in the distributor. May check it out if haven't already.

Possible fuel pump comes to mind(only because if not gone out fully may act up first). Crankshaft Position/Angle Sensor, Camshaft Position Sensor. Also if you can be ready to check if you have spark or not and if you have fuel or not when it does not start would be helpful in diagnosing the issue. May check fuel regulator.

I have had most of all those things check out and or replaced. It starts good when its cold outside or when its hot and the engine has cooled down, and once you get it started it runs good. It most times will start, but it runs really rough and then finally kicks in. It does act as if its staving for fuel, but I had both fuel pumps changed on it. And like I said, it only acts up on days when the temperature out side get up to or above 75 degree or so. Thanks so much for taking the time to try help me on this truck. I had a 1987 F150 that I had 250,000 miles on and it ran like a trooper. It was all rusted out, but engine wise not problem at all. So I bought this truck used with about 30,000 miles on it. I now have about 130,000. It never did this until about 4 or 5 years ago and the mechanics have tried all they know but after hundreds upon hundreds of dollars, they haven't helped it a bit. I think there's got to be someone out there that can hit the nail on the head, as this can't be the first ford to ever have this problems. Again thanks to all of you for your time and information.

I do have spark and do have fuel. I have had those checked.