Question : why does car run great in cold weather but poor

[tkjackson02]

been having issues with my 95 Beretta Z26 with the 3.1. all last summer it ran like crap hesitating, stumbling, and occasionally died at stops. But soon as the cold weather hit it started running great. So now that the weathers starting to warm back up the old problem has showwed its face again. At a loss on what to do would greatly appreciate the advice. Thanks!!!

[1988GTU]

Icm/coils or Max would be my guess

[ridiculously_necessary]

possibly the egr valve needing a cleaning...