99 F250LD 4x4 w/5.4 and 215k . I'm sure I'm not the only one with this problem. Just had quite a bit of rain in my area. I didn't drive the truck in it but 3 days after the rain stopped I did. Skipping badly ! It has done it before and will clear itself up after a heat cycle or two. This time it kicked a p0307
code. # 7 cylinder not fire correctly I believe. I got ready to replace the cop
but decided to wait a day. In the mean time I pulled the connector and blue
compressed air through it and the male connector. The next morning I decided to drive it before replacing the coil. Absolutely no skipping at all. Drove at different speeds , up heels slow , high speeds, no skipping. Ran the truck for about 20 minutes or so. Is the connector getting moisture in it ? Can I fill the connector with dielectric grease? Is there another problem. I cleared the codes and am going to drive a couple of cycles to see if any come back but any suggestions would be appreciated. Like I said it has done this before but not bad enough to throw a code so I'm not sure if it's always number 7. Thanks for your help

 

that's exactly what happened to mine. Dry days it's fine...
never a code though.
to this day I'm not sure...she's in storage for now. Was going to replace the COPS.

 

The connectors to the cop's and injectors have weather-pac seals around the male end and also encasing each wire going into the connector. Sometimes when engine work is done the outer seal falls off or is damaged trying to plug it in if it's not clean. Check to make sure the outer seal is there. Dielectric grease shouldn't be needed for the connector. Did you remove #7 cop to check if water had filled the spark plug hole? Dielectric grease is used sparingly inside the cop's boot where it slides over the spark plug. Sometimes old reused distorted boots on a plug change may allow water into the plug well as they don't seal well.

 

no water in boot or spark plug hole. Running like new at the moment. I cleared the codes and began a driving cycle. I really can't see how just moisture in the air could cause problems for so many. I didn't even drive mine until two days after the rain stopped. ???????????

 

no water in boot or spark plug hole. Running like new at the moment. I really can't understand how moisture in the air can cause problems for so many. I didn't even drive mine until two days after the rain stopped. ??????????? I cleared the codes and started a driving cycle too see if the
cel comes back.

 

Mine drove me crazy on the passenger side whenever it rained......even just parked. Was always #2-3 or 4 as a code...would be water in the well. Was not the hood seal, not splash up (was parked) not a heater hose (clear water). Finally slowly open the hood after a big rain and here it was leaking in by the squirter, dripping on that black electrical shield and flowing directly down to that valley that all the plugs are in . Then it would flow around and end up in spark wells.