humid distributor


Old 10-06-08, 03:16 PM
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humid distributor

Hi. My 97 civic stopped starting when it is humid out. I manage to start her by blowdrying the distributor cap for a couple of minutes. I'd like to fix this without buying a new cap because i don't see any cracks or damage on it, and can't find a replacement o-ring. does anyone have any tricks? i saw a product that you spray on the distributor cap that supposedly protects it from moisture. has anyone used something like this before?
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Old 10-06-08, 04:34 PM
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With my old Toyota pickup, I would always spray some silicone all over the cap and plugs. It came with a rubber cap cover, but that didn't do much when there was high enough water that it would come through my doors. The Silicone seems to help.

BUT, I've never heard of jsut plane ole humidity doing this to a cap... are there visible signs of moisture?
Old 10-06-08, 05:19 PM
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Used to be an old trick of drilling a couple of vent holes in the sides of the cap itself. Used to work ok back in the old days. Not sure if that would apply anymore.

Take it off, wipe it out real well with alcohol. Check for any carbon tracks between the posts. Spray the outside with silicone and use a little boot grease on the wire boots.
Old 10-06-08, 05:33 PM
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Cool out and humid, or hot out and humid?

If cooler out, the cold vapors would condense inside the hotter-inside distributor on the same principle as sweating occurs on cold windows on the INSIDE of the warm house.

As an experiment, if you can't find a gasket or o-ring to fit, you might try some of that caulk that has the ability to be peeled off when you want. It is used for weatherstripping and is sold in home centers. You could pop the distributor cap off, caulk the rim and stick the cap into the caulk and tighten down and let the caulk set up and see.

If your car's distributor cap has it to where the plug wires go right through each tower and come out on the inside, this may be more problematic. Then you'd also have to make absolutely sure every boot is snug, for sure.

I knew someone whose car did this everytime the sea fog/mist would roll in. And this person got quite annoyed at having to pop the cap all the time and spray WD-40 under the cap to get it to start, especially when having to leave in the dark for work at 5 in the morning.
Old 10-06-08, 09:03 PM
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thanks for the replies.

hotinOKC: yeah, just high humidity. not even any rain, and there were no obvious signs of humidity, except the cap bolts are rusting. wait, i guess that is an obvious sign of humidity. i'll try the silicon spray. if it helps you when you're submarining your pickup, it should help my little civic.

Gunguy: i had someone else recommend drilling holes in the cap, so it probably still works. still, i'll try that last. i'd love to take a look at your tool box...alcohol, boot grease...what else do you got in there? and another thing, it's funny how Gunguy's solutions involves making holes in things. fixing stuff and target practice go hand and hand with you, no?

ecman: mild and humid, really. she wouldn't start only if she had been cold for at least 4 hours, and it's humid out. once she's warm she would start no problem, so i'm assuming the temp. is the same inside the cap as it is outside. But you're right, it is a condensation issue but i'd say it's more of a morning dew thing than a cold/warm issue. either way, the seel must be breached. i like you're silicone caulk idea, but if you've never tried it, i'm worried it'll melt or something. silicon spray sounds safer so i'll try that first.

thanks guys, i'll let you know if anything works.
Old 10-07-08, 08:00 AM
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Check inside the cap for carbon tracks. If there are any, that could be part of the problem. Also, try starting it at night, in dark place, with the hood up. You may see a real light show which will visably show you where to make repairs or space wires away from metal etc.

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