1995 Sunfire fails to start occasionally

My daughter's 1995 Sunfire fails to start occassionally. My next-door neighbor is an auto mechanic and finds no codes when he hooks up his tester. However, it starts fine the next day. This has occurred 3 times since December. I thought it might be related to cold or dampness.
Any ideas before I spend the money to take it to a Pointiac dealer?

2.3 liter 4 cyl

thanks

fill a spray bottle with water and salt. start spraying stuff down while it's running it's probably the coil pack

I had the same problem with my 96 sunfire, some mornings it would start and others it didnt. It always seemed to do it when it was cold. We replaced my spark plug wires and its started right up ever since. Just thought Id let you know if youre still having problem with it.