03'-3.8 stalls 1 time when cold.fine when warm

Ok my daughters 3.8l stang will die 1 time if its not at operating temp. it idles perfect, no codes(so far). I did a full tune-up plugs wires air and fuel filter cleaned (maf). so this morning she lets it warm up 10mins goes to school fine now after school she hops in and again no warm up stalls out at 1st stop sign. this has been happening everyday cranks right back up and no more issues. what ever it is it happens when cold. So being a teenage girl all i get out of her is "it just quits" since i havent been able to get ahold of it when cold yet, looking for a little help. ( Just a little info for the young guys out there. if your girlfriends car is messing up, its probably not a good time to want to run around in HER car. unless you want to piss the father off) you cant buy better advise.

Even though you cleaned the MAF sensor, it still could be bad!

I'd suspect a sticking Idle Air Control Control (IAC) valve.

Since her mother finally made her leave the car home i went back out and drove it and the result is the water pump. she failed to mention that when its cold it squeals pretty bad and you can feel the pump locking up to the point it almost stalled on me. but im sure with the radio up and heat on high she never even noticed so im pretty sure thats it. thanks for the suggestions i did forget to check the IAC so while im changing the pump i will give it a look.

I replaced the water pump and idle pulley on a whim(should have just took the belt off and ran it for a min) its not the water pump. I could almost swear its internal like crank bearings. um. the cap says to put 5w-20 and i put in 10w-30. can this be the culprit? it has 53,000 on it. or is this problem the reason this car was traded in? my plan now is to drain the new oil and pour in 5w-20 and a quart of dura lube. i really do not want to pull the pan off. any suggestions? it not the tensioner or the a/c comp. or the alt. or the p/s pump.

crankshaft angle position sensor. if you have a squeaky noise coming from your engine and cant figure it out, thats what it is. i almost pulled the oil pan. whew.... i hope this helps someone from the headache i had.