Engine Running Rough

I have a 1998 Chevy S-10 that misses/hesitates at 1500 - 2500 rpms, This condition is most evident when the outside temperature is below 40 degrees F. The spark plugs and wires, coils, crankshaft sensor and ignition module has been changed. Any suggestions?

The air/fuel ratio is off at those rpms. Check the engine coolant temperature sensor. Here’s how: http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c152800bfd33