Grand Marquis starting problem

Okay, I signed up on crownvic.net, but still haven't been approved, so I figured I'd ask the vast knowledge base here at GRM for an idea.

Over the last few days, starting on Friday, my 2000 Grand Marquis almost stalls out as soon as I start it, but then settles into idle within a few seconds. Basically, starts up fine, then immediately RPMs fall to almost stalling, then it comes back up. This morning, it actually stalled, and I had to give it some gas when starting to get it to go, but as soon as it was idling, it was fine. No driveability problems either, this is only on startup, when the engine is cold. Starting it up when the engine is warm, its fine.

My first guess is the throttle body is a little gummed up and not letting enough air through when closed. My second guess is the IAC is bad, but I'm not getting a CEL. Other than cleaning the throttle body and seeing if the problem goes away, any ideas?

I have had this issue with a couple of Panther bodied cars, it is the throttle body, clean it up, use some Mystery oil and it will go away. Mine has done it regularly then stopped when cleaned and some time later started up again, recleaned and it went away yet again.

I was thinking idle air control valve. As said above remove, clean, reinstall, repeat as nessesary. I had another Ford do that then start holding high idle. cleand and solved the problem.

The older 5.0 cars had an inverse problem where they would die if left to idle too long, and it was due to the IAC. Try unplugging the IAC to see if it runs differently, or cleaning it up.

The mod motors in the trucks could stall immediately after startup when cold due to a sticking egr valve, but it sounds like throttle body gummed up is also a cheap enough fix to try first.

Cleaned the throttle body. It was a bit dirty, but not too bad. We'll see if that fixed it tomorrow morning.