Post-startup engine flutters

My wife has been telling me that her 2000 GT 3.8 has been stalling out on her after she starts it up. Doesn't do it as badly in the winter when temps are cooler. But if the car is up to operating temp, and she shuts if off to run in a store, say 15 min., then starts it back up, the RPM's flutter up and down from about 200 - 2K, then the car will just die. It'll start right back up and be fine until you do that all over again. I replaced the LIM gasket a couple years ago, and it kinda seems like it began doing this periodically since that. I've sprayed carb cleaner around the intake area a couple times, and noticed a very slight increase in RPM's, but never could pin-point down. I have no idea what else to try. Anyone here have or have had this same probem?

I have just recently and today had to be towed home because I couldn't get it re-started, would start and run for 3-5 seconds and die even with foot to the floor, almost sounded like running out of fuel but it has 3/4 tank and I can hear the fuel pump. Mines a 97 BTW.

Could be a sticky IAC valve. Is the MAF clean?

When you did the LIM gaskets did you remove the TB from the UIM? Could be leaking vacuum there causing a wierd idle. It's also possible that your UIM is warped/cracked and causing a vac leak. I went through that before I finally replaced mine. After that, nice smooth idle.

try unplugging the maf but i donno it that could be bad enough to cause it to not run at all. mine fluttered on warm restart and new maf fixed it

Mine ended up being the fuel pump resistor, did the relay mod on this site.

I replaced all gaskets when I did the LIM. I've replaced the MAF, and even cleaned it. I've also driven with it unplugged, but no change.

Strange thing is, that the car does this mostly in warmer weather. During the winter, it hardly ever does it. Now that its warmer out, its doing it all the time. Would a vac leak be worse in warm temps over colder ones? Would a IAC valve cause this to happen when its warm out? I'm willing to do anything to fix this thing. Its driving me crazy!

Car doesn't do it when the engine is cold, only after its been ran for a while, shut down, then re-started.

I ordered a new EGR tube today for it. I'll try that this week and see what happens.