cold start problems
 

My Stang is running very rough when it is first started when cold.It will stall and then run like sht.until it warms up.What might be causing this

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90 LX GT40 ALUM.HEADS 65MMTB,GT40 UPPER@LOWER INTAKE 1.7RR'S SHORTY HEADERS,E303 3.73'S,K@n
dynomax catback,march pulleys.

I've had those symptoms 3 diff times, w/3 diff solutions. first time was sticky EGR valve - took lots of vac to pop open, found it by swapping valves w/another car that ran good after code reader said EGR system problem. Next it was the EGR position sensor mounted on the EGR valve. Last time it was the little valve in the Idle Air Speed motor assembly that was full of deposits and sticking. Sprayed w/carb spray, used tiny brush (don't gouge the valve) and blew it out, fixed again!