'94 pickup problems with rain

My '94 pickup has idling problems in the rain. Seems like something gets wet, the idle slows like it's going to stall. Yesterday, it did. I was able to start it again, then it ran okay. I made 2 more short trips, then, when I started it, the check engine light came on. I had spark plug wires/dist. cap changed, and engine tuned up. Any other ideas? Thanks.

Could be one of the many sensors is getting wet. The CEL may be giving you a clue, check the ECM for error codes. If you search you will find the instructions.

Also depending on your engine type, your dist. cap may had a o-ring or gasket. Next time when your engine gives you troubles pop off your cap and see what's going on under there. if it's wet, it'll cause a misfire and trip your check engine light.