1999 F150 5.4 Iac is not Working at all Changed it Nothing not even a hint it was working Idk Whats left to do on it any help would be great Put a new Head on it 6 mths ago and idk if it worked before or not Vacume line unplugged?????

 

I'm going to assume that your truck don't idle or idle bounces around, try to take the air cone off and find the hole that allows the air flow to the IAC, see if its clogged up and if you can idle the truck put your finger slightly over the whole to see if the truck idles right. if that don't work check all the wires that lead to it to see if one is cut or burnt, and again with all the vacume lines. How did you test the IAC to know its not working?

 

well what I have done is replaced it and I did a deeper scan today no check engion light but in mem a idle air contoll system code no numers tho

 

It is really difficult to tell what is going on with your truck but you could have a EGR issue also. It doesn't cost anything to check for a stuck EGR so you should do that. If it is stuck, you can clean it to get it working again. Also make sure the tube between the manifold and egr is not plugged up.

 

Check the egr, evap, etc thread