jrdiebolt

I have a 1996 F150, 155,000 miles. When the weather is hot and the engine is hot, it is hard to get the engine started after it is turned off. This only happens when the weather is hot (above 90F) When it starts it feels like it is hitting on 2 cylinders, then in a few minutes it will begin to hit on all cylinders. There is a a heavy smell of unignited fuel until the engine begins to hit on all cylinders. There are new plugs and wires, new rotor cap, new ingnition module, new crankshaft module. I have had the truck to mechanics and they cannot find the problem. Any suggestions on what may be the problem?