94 F150 302 Fires right up no matter how cold. Idles fast for about 6 to 8 seconds then dies. Starts back up no problem. After restarting it idles fast at first and gradually slows as it warms up. If it's above 35-40 it just stumbles and then catches instead of dieing. Why?

 

First, have you replaced your fuel filter. If you have water contamination it could be causing restriction. Dump in a can of HEET or like product. Check the fuel pressure with a gauge borrowed from a parts store at the schraeder valve (tire stem type) on the fuel rail. Check the distributor cap for condensation also.