Stumbles when it is wet/raining...

[johnboneske]

I have a 97 with a 5.4, a little more than 209k on it.


Here is the weird thing... when it is raining it stumbles. Only cylinder #8. I have changed the coil pack on that cylinder twice(all have been done actually). All new platinum plugs in it too. I checked the wires feeding the coil pack and no cuts/marks/abrasions. I pulled the coil pack and no water in the hole. I always get a CES light and scan it and it is always #8. Reset it and it goes away when it is dry... Confused how I can change the coil pack a few times and it still misfires sometimes?

 

[bedrck46]

Check the wiring that connects to #8 for any bare spots, burns etc. Also look at the connector for any signs of corrosion. Get some Noalox and put on the connector google Noalox can be purchased at Lowes

 

[johnboneske]

I have used dielectric grease on the wires and have checked them for abrasions...nothing! Confused...

 

[bedrck46]

check the connector that goes to the PCM Also there is a 16 pin connector in-between the coil pack and the PCM connector It is located on the right rear of engine compartment (passenger side) for any signs of moisture corrosion etc.

 

[hades02]

radio noise suppressor is a possibility. There are two, one on either side of the front of the engine. It rusts out and causes stumbling when they get wet. Hope this helps