Here is my problem
 

I have a 1996 Mustang GT. Now i do live in arizona yes very hot 120 during the day. and i drove the car all last year, bat at out of hell, moderate you name it no problems. and just recently when im driving my rpms drop and when i give it gas i get nothing.. and when i come to a stop the car idles very very rough and knocks a bit... so ill turn of the car.. and hte car will start, but once motor reaches idle speed its idles rough and eventurally dies... but if i drive the car at night or early morning it runs fine.. so something under the hood is over heating.. ive checked the coolant temp sender, maf seems fine, replaced tps, only things that i have not replaced are egr valve, egr valve pressure sensor, fuel regulator, pcv valve and O2's. or it could possibly be a coil pack intermitently going out to i guess... any input would be great...

IAC

throwing any CEL codes?

IAC? .. no ive thrown my scanner on it several times and pull up no codes, the check engine light doesnt come on at all... i can drive it in teh morning, and at nights at normal operating temps no problems.. its mid days like when it hits 120's and what not when it acts up...

ive checked my IAC.. and it seems to be getting the sufficiant power it needs.. and i checked the valve itself with my volt meter for resistance and the valve seems to be working.. it doesnt normally happen at idle.. it happens when im going about 50 down the road about 2300 rpm.. and the whole thing just seems like it shuts down.. but when it idles rough its almost like vapor lock.. hasnt done it in a couple days now.. im getting ready to do like a complete fluid flush.. radiator, oil, tranny... and put new fluids.. and new spark plugs and wires.. see if it may be something there... maybe new coil packs to just to get the whole tune up done...