Rough run after moist weather?

[ks10308]

Hi so I have an 00 4.6 4x4 with 143K miles. The car works fine and has been pretty well maintained but there is a rather annoying issue. Lets say the car sits overnight when its extremely humid or theres rain (and it sat for 2 days when all the snow was melting). I would turn the car on and there would be a really rough idle, like a misfire. And when I would drive off it would persist but then disappear as the engine warms up. The problem would go away after 20 min (one time 45 min due to the stubborn snow) after the car is fully warmed up and running. Any ideas? Thanks guys

 

[IMINYOURCHAIR]

Edit: Wrong thread. Hope you get the prob solved

 

[bedrck46]

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[Petesexpy]

Check your COPs. Any codes?

 

[FordandPolaris]

I would agree, more than likely you are getting water pooling in one or more of the spark plug wells causing a ground to the block instead of through the plug. The rubber boots on the bottom of the COP tends to dry up and no longer make a good seal. The engine warms up and evaporates the water, and the problem goes away. Unfortunately it's only going to get worse, start looking into replacing plugs and COP's. Lots of threads on the topic.