new form I need to pick some brains

[Phoenix]

Hello nice to meet all of you here's what I've got 1994 Yukon 2 door 5.7 auto trans 4x4 wanted one for a long time and just bought this one a month or so ago was my dream truck but has become my nightmare when cold she cranks idles for 5 min or so and dies will start right back up but dies after a few sec but if I put my foot on the gas and hold it at 1100 rpm she runs like a top and drives great but as soon as I let her idle down she dies I've replaced (with new parts) in this order the sparkplugs, wires, cap, rotor, deleted the cat put headers on it then the PCV, IAC, TPS, Ignition Module and the Coolant temp sensor and still she has not changed at all but does run better then when I got her just dies HELP ME PLEASE!!!!