1985 Convertible GT 5.0 EFI H.O. Garaged for 20 years

Hi, I just acquired a Mustang that's been sitting in a garage for 20 years. Aired up 2 tires, added 5 gallons of 91 octane and filled up the radiator. The owner had opened the petcock and drained all the radiator fluid when parking it. I also put in a new battery. Turned the key, fuel pump came on for a little then shut off. I cycled the key 4 times and turned it over. I fired right up and then stalled out. I started it again and again, it shut off. I did this about 15 times and while feathering the throttle I could get it to stay running, but it always died. I replaced the fuel filter by the tank, didn't help. I looked at all the vacuum lines and all looks good. From what Ive been learing, I'm wondering if it could be the IAC or TPS or the MAP. Any thoughts or ideas would be most appreciated.
Thanks.