Rough idle after rain or humid

jslim32

I'm new to this so we'll see how it goes. I have a 1999 ford escort that normally runs great, but after a rain or when it's humid (even when parked in a garage) it will idle rough for a minute or two and then be fine. I've only noticed it after rain or when it's humid. I've changed the fuel filter, cleaned the idle control and throttle body hoping this would help, but it rained last night (car was in garage) and with a little extra humidity...rough idle again today. Anyone have any suggestions or fixes for this? Thanks in advance - cheers!

93tracker5spd

Hello! Welcome to Edmunds. I am going to state the obvious here, something electrical is getting wet or damp with the humidity in the air. Sometimes can be a tough search, I would wait for a rainy night, go into the dark garage, open the hood, then start the engine; quickly look into the engine compartment, (keep hands out, MOVING PARTS) and look for blue sparks arcing from plug wires, distributor cap, etc. Or, in day time cover each electrical ignition part with plastic wrap, unwrap one component at a time and mist the engine with a garden hose, just mist not full spray, until you find the rough idle, then you will know which component is the cause. The third option is to simply do a full tune up with all new electrical components, about $80 - $100 and that should clear it up. I would go the cheap way and find out first, that's just the curiosity factor with me; I would want to know the exact cause. Good luck to you.