Misfiring in the rain

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Old 02-22-2011, 09:20 AM
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Default Misfiring in the rain

Hey guys, this weekend in Phoenix we got our yearly back to back days of rain which means I get my yearly misfiring from my engine. Whenever it rains my car decides it wants to bog down in the lower RPMs and sputter if I try to accelerate faster than grandma. So I dragged it down to O'Reilly and the machine read that cylinder 3 was misfiring. The guy said that depending on where that cylinder is located on the block water might be getting to the plug. So I went home and found that the plugs do face towards the ground and cylinder three is the front cylinder on the block. Now normally this wouldn't be a problem because I just let it dry out and it works fine within a day or so. But my problem is that I'm going to be moving back east in a couple of months and I know for a fact it rains more than five times a year and I don't want this to be an everyday problem. Do any of you guys with 4th gen V6's experience this problem and if so what do I do to fix it? Thanks in advance.
 
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Old 02-22-2011, 09:45 AM
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You could try a set of new plugs and plug wires. It is possible that the wires have dried out with age or that the boots are no longer fitting tight, thus allowing moisture to be absrorbed and create an easy path to ground and cause misfire. Worn out plugs wind up with gaps that are too big which then requre more voltage to fire. When this happens the spark looks for the easist way to ground, and if the plug wire insulation is weak, the spark will jump across the insulation, and again cause misfires.
 
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Old 02-22-2011, 10:03 AM
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^^^ agree, most likely a bad wire. could be a cracked plug too. do you have the heat shields in place? if so make sure they are not rubbing against the wires.
 
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Old 02-22-2011, 10:38 AM
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^^^I agree here too about the plugs and wires. Get new and use dielectric grease on the boots to prevent moisture intrusion. Also #3 is not on the front of any head it is the middle of the driver's side head. Look at the picture I posted below and it will show you the cylinder layout and the coil layout as well. Make sure you put the little metal heat shields back on the wires especally #3,4,6

Massey
 
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Last edited by Massey; 02-22-2011 at 10:42 AM.
  #5  
Old 02-22-2011, 10:45 AM
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Originally Posted by GoofieJ21
...So I went home and found that the plugs do face towards the ground and cylinder three is the front cylinder on the block.
I hope you based that on speculation, and not because you have the #3 coil wire going to the front (#1) cylinder?
That would mean crossed wires, but the engine would then run crappy all the time.
 
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Old 02-22-2011, 12:35 PM
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#1 I hope it's not the plugs or wires because I had them replaced a little over a year ago and I'd hope they wouldn't go bad this quickly.

#2 I said #3 is the front drivers side cylinder because I followed the coil wire down to where I believe the wire went. It's difficult to see which wire I'm pulling on from underneath of the car. So I'm probably wrong.

Another question I have is does the water getting on the caps make them go bad more quickly than not. When I move back east am I going to have to change wires every year or so? I just thought there would be some sort of protection for the caps and plugs from the elements. That may be ignorant thinking but I don't want to have to buy wires that often.
 
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Old 02-22-2011, 01:02 PM
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pop the hood, and pour water on the windshield, see if the cowl is letting water in.
 
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Old 02-22-2011, 01:05 PM
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There could also be a crack in the housing of one of your coils. Move the first and middle coil on the ICU and see if the missfire moves from #3 to #5. If so you have a bad coil pack.

Yes water can cause a short to ground in the ignition system. Use Dielectric Grease to help eliminate this. Also if you dont use the heat shields you can ruin a set of wired in a few minutes. most part stores will not cover burnt wires under warranty.

Massey

P.S. dont forget to move the wires as well as the coils. Dont leave them attached to the coils after you move them.
 
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Old 02-22-2011, 01:24 PM
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Any recommendations for brands or types of plugs, wires and grease?
 
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Old 02-22-2011, 01:52 PM
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OEM plugs for 99+ were Iridium, Delco made by NGK. I would put either AC Delco or NGK Iridium plugs in. Make sure you gap them carefully since there is such a small electrode. Wires if you are just looking for OEM grade go with Borg Warner. As for the grease it is all about the same then just get one or two of those little one use puches that the part store sells you should be fine. If you want better than OEM wires I have heard good stuffs about the MSD wires. Just remember no matter what wires you use, dont forget the metal shields to protect the wires from the heat of the exhaust manifolds.

Massey
 


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