1996 Chevy Cavalier car won't start when it sets out in the

My girlfriend's car when it set in the rain it won't start,

Next time it refuses to start do below and tell me what happened.

Disconnect a sparkplug wire or 2 and ground it to the engine -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs, distributor pick-up coil, ignition control module, cam and crank sensors- Note: If it doesn't apply disregard it

Raz is right, The bst time to see if anything is sparking is at night with no lights on. This way you will see and hear if something is shorting out.