How water-resistant are the late model gas caps?

Odd question, I know...
This weekend I was finally give my truck a good washing. I cleaned out the the gas cap area, and lightly hozed it out.
The truck ran fine all day yesterday, granted I didn't drive all
THAT much.
Yesterday, my truck was running on the crappy side, and threw a fit when trying to back into a friends driveway. It kept wanting to stall, and would drop RPM's to about 250 or so. (Yeah, two hundred and fifty). It would rev fine in neutral or park, but when you let off the throttle, the rpm's would bounce from 500 to 250.
My first thought is that I got some water in the gas.
Your thoughts?
The truck is an '04 Silverado SS.
Thanks, -marc
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If your gas cap wasn't sealed air tight you'd be getting a Service Engine Soon light and a "Small Leak Detected in EVAP system" error code. So in short, no you don't have water in your gas, it's something else.
Doc
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\"Doc\" wrote:

I didn't even think of that. Half of the vehicles I own have vented caps, and I just wasn't thinking clearly.
Whatever it was, it's gone... so...
-marc
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Hello
By any chance did you hose off the engine? If so you may have gotten water onto the plug wires or into the distributor. Another possibility you may have knocked lose a vacuum hose. Is the Service Engine Soon on, it should be and if so what codes are coming up?
Good Luck
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krisstarr wrote:

No, I didn't get any water under the hood...
I didn't get any SES light or codes either...
Weird.
-marc
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water
Change fuel filter, if the problem comes back. If that doesn't clear up the problem forever, check the fuel pump pressure.
--
Diamond Jim
"The Old Devil Dog"
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