Random Low Idle

[Raptor05121]

Well the other day I installed my HIDs. So I undid the negative (-) side of the terminal of the battery. I finshed up and my lights worked, etc. But upon startup and warm up, I noticed that my truck isnt idling at the normal 800 rpm but like 640...then 720....then down to 670....then up to 705...like jumping around. Then I kick on the A/C to see what happens and it drops as low as 530! It sounds as if its going to stall. When I drive around and go back to idle, it will sometimes stay at 800, I drive some more and go to idle, this time it acts up again. Its totally random and the only thing I did to it was unplug the negative terminal. How could this mess up my idle? I think I might replace the plugs and wires next week.

[Justin61391]

SAME thing is happening to me right now. I've been searching for the correct idle speed at operating temp for half an hour but to no evail. I have a hayne's shop manual but can't find it. I was thinking around 775-825 was normal?
truck is shutting off on me sometimes becuase it idles too low. Even when cruising, if I am not on gas sometimes it shuts off because it idles too low. I think i am going to go to auto zone for a diagnostic soon....if this keeps up im going to wreck via not being able to turn and brake as good.

[ManualF150]

Check the Idle Air Controller... it's that shiny thing right after the rubber intake mounted on the throttle body. It might just need to be cleaned/replaced.

[dixiedesign]

When's the last time you cleaned your throttle body? Mine all of a sudden started doing the same thing, then I cleaned the throttle body and it runs like new!