89 F-150 Very Rough Idle

I have an 89 F-150, 4.9L. It Idles very rough,First start always stalls. Second start stays running. I have changed : Fuel Pump, Fuel filter, TPS, Map Sensor, Plugs, Wires, Air filter, PVC. Cleaned IAC and fuel injection. I have checked for vacum leaks and found none. Any suggestions?

EGR valve comes to mind. let us know.

ervinj