2000 Ford F-150 Idle low

First, I am not getting any codes.
I would start my truck and it would stall out unless I kept giving it gas, even at red lights, so I put two bottles of fuel injector cleaner in and that helped.

But now when I start it, it still wants to stall out, it's like the choke will not kick in to get it going.

Is there a choke sensor? What makes the choke kick in?
I don't want to go straight to raising the timming because once it runs for a while the timming is fine.