No Idle for a while (intermittent)

1999 Grand Marquis LS (~60,000 miles). It does that from time to time, I have to keep my foot on the gas pedal for a while, otherwise, it *will* stall. (it doesn't idle)
Happened again yesterday, had to play with both pedals for a couple of stops & redlights before it could idle on its own. (after about a couple of minutes, it's fine)
Tried to figure out a pattern (warm then cold, dry than damp, but no match)
The only pattern I can see is I get a little surge of engine power when it gets OK.
A friend of mine suggested removing the IAC valve, cleaning both connectors, and cleaning the IAC itself using carb cleaner. Kinda makes sense to me.
A vaccuum leak would do it more often than once-in-a-couple-weeks, unless I'm mistaking...
Any ideas/suggestions/insults ?
:)
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On Sun, 16 Dec 2007 19:07:42 -0500, El Bandito

What you have are the classic symptoms of a dirty IAC. This is probably the most common cause of stalling at idle. You should be able to turn the a/c on/off and put it into gear with no perceptible change in idle speed or quality if it is working correctly. Sometimes, they can be cleaned. Others, they require replacement. A dirty one will not set a fault code or illuminate the CEL - only an electrically failed one. The quick down and dirty way is a new one that will cost you $45 to $100 depending one where you get it.
Lugnut
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wrote:

I'd vote IAC valve, too. Bought one at a dealer in 2003 for $130 for my 97 CV. Trying to clean my old one just made it worse.
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El Bandito wrote:

I've had great luck cleaning my IAC. Didn't have to get as harsh as carb cleaner. In fact, I'd be a little nervous about going that strong.
Never bothered with the connectors. I had some instrument cleaner left over from cleaning the MAF and when that was gone I used WD-40. Just sprayed down onto the shaft, let it sit, move the spring around a little, blow it out and it has always worked for me on my 97 4.6. (167K)
If you have a small brush you can stick down in there so much the better.
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