Hyundai Repair: Poor running engine/idle at cold start ups, hyundai accent, start ups

Question
2000 Hyundai Accent 1.5L engine with 110K---engine "stumbles" idles rough at first start up (especially on colder mornings) Drives very sluggish until it warms up then runs fine remainder of the day.  Any idea what problem is?  Thanks

Answer
First, you should check for trouble codes and diagnose and repair anything that's left a code.

If you've got no trouble codes and nothing else identifiable seems to be wrong, then you should probably take it to the dealer.  There's a reprogram available for the engine control module to correct "poor or delayed acceleration when driving after an initial cold start."  Full information is available in Technical Service Bulletin 01-36-013.