moisture issue o2 sensor?

[johnyreb]

I've been having an issue with my truck running a little rough when it's wet out wich is here lately is always after a day or 2 of it being dry it straightens out and runs great if i splash any water on the under side of the truck it runs extremely rough and losses a lot of power and the more throttle i give it the worse it runs but it still idles fine i assume that its something electrical getting wet my best guess is the o2 sensor any thoughts suggestion on what to check and how to fix it would be awesome

[Precise1]

First, check the ECU for stored fault codes, the instructions are in the Garage/How To section.

 

Any time you have wet electrical issues, WD-40 is your best friend. Carry a can and next time you have that issue, spray a few things you suspect (take apart connectors and spray them as well). Just make sure to only do one at a time between tests or you still might not isolate the cause...

 

B

[Alkorahil]

Like Precise said, check the ECU see if there is anything stored. It might help figure out what the issue is.

 

Do you have a lower skid plate and are the rubber side skirts in the front fenders intact?

 

I suspect the cause will be water in the engine bay splashing up on something more than undernearth teh chassis.

 

I am thinking its water on the distributor cap. Some caps have a breather on them and water can get in (been there) or poor seals around the base allowing some moisture inside.

If you pop your distrubutor cap I would not be surprised if there was condensation inside, which can cause some arching inside the cap. ON a non-humid day I would get a can of wire dryer, http://crcindustries.com/auto/?s=05104 its about $3 for a can and spray the inside of the cap, let it dry and then use a small amount of white lithium grease on the lip of the cap and re-attach it to the distributor. A small amount of dielectric grease on the cap would be ok too.

 

ALSO

the spark plug wires have DEEP galleries that water (and other crap) can fill up with. The heat of the motor will evaporate the water but it can play hell with the spark plugs making contact with the wires for a moment if you have old spark plug wires with bad sealing boots and/or no dielectric grease on the spark plugs. You can pull your wire off the spark plugs, get a flashlight and see if any rust is developing on the spark plugs or inside the wire boots.

 

Do you have any warning lights comeing on when this happens?.

[johnyreb]

No warning lights and no codes stored i did wrap the o2 sensor in some electical tape and that helped a lot untill i splashed through a mud hole a bit faster and splashed my motor so this weekend i planed to replace the plugs anyway so i'll do some water proofing there as well

[Alkorahil]

Good deal. I think this will solve your problem. It has worked for me in the past with water/mud getting on the motor.

another hint, if you have access to compressed air. remove the spark plug wires THEN blow out the galleries with compressed air, lots of stuff/trash/mud/crap can collect there and fall into your cylinders when you pull the plugs out.

Edited June 7, 2013 by Alkorahil

[johnyreb]

Unfortunately i don't have access to compressed air and actually my tool kit is very limited now some a$$h0le stole my entire tool box today while i was at work

[5523Pathfinder]

Ya know, there is a TSB for water getting in the o2 sensor connector and it would cause a misfire. I will have to do some digging to find it.

[Precise1]

Unfortunately i don't have access to compressed air and actually my tool kit is very limited now some a$$h0le stole my entire tool box today while i was at work

Crap, sorry to hear that, I have had it happen before myself...

 

As for the compressed air, you can get a can of air used for cleaning electronics. While it isn't unlimited blasting, using the straw and some judiciousness will go a long way. I use them all the time when I don't want to break out the compressor and they can be handy to keep in a tool kit.

I recommend you remove the plug wire, look down with a flashlight to see what is in the well, use a stick or something to loosen things up if appropriate and then give it a blast or two to hopefully clear things out. This should always be done with all vehicles, you really don't want crap in the cylinders! Remember, if the straw isn't long enough, you can splice them together by pulling a slit in one straw for about 1/4", put another straw in to it as far as it will go then seal and connect them with some tape...

 

B

[johnyreb]

Well i got the plugs went with ngk g powers and before i got a chance to put em in my battery just up and quit no warning at all its just been one of those kinda weeks thanks for all the help and suggestions i'll definitely try the air duster thing and hopefully after new plugs, batter, and some more water proofing i'll be hiting the trails again soon i had been wheelin almost everyday since i found some fun trails literally walking distance from my house now it feels like its been forever