Dampness = rough start?

[GrossMan]

My '98 with V6 144K miles has started this nasty behavior whenever it sits overnight during rainfall or extremely high humidity (over 80%).

My 4runner is parked outside and ,after an overnight rainfall, I start her up she rumbles and sputters and very nearly stalls. But, if I let her idle for 8-10 minutes she settles down and runs smooth as silk, like nothing happened. No CEL or other idiot lights.

I'm guessing that the spark-plug wires or coils are involved, perhaps condensation causing a short and after 8-10 minutes the heat of the engine dries things out?? We've had several days with temps around 4-5 degrees but with very low humidity and she starts right up without a care in world. So the issue, whatever it is, has nothing to do with "cold" starts.

thoughts?

 

[kball]

When she starts rough any smoke out the exhaust? I know when things get moist it will exacerbate a bad battery connection so you might want to clean that up if there's any corrosion there.

 

[LittleCaesar]

Pop the hood before you start it after a damp night etc., and see if there is any arching anywhere. If either engine had a dizzy, I'd tell you to check the cap first.

If the wires are original, start there for some new NGKs for $30. Check each coil's boot condition as well.

 

[GrossMan]

Kball, no there is no smoke from exhaust. The batt is new this past July, but I will double check the connections.
LittleCaesar, I had not thought of looking for arching - brilliant!

Thank you Gentlemen!