i have a '86 F150 with a small problem. it is a 302 automatic and after it has been running and comes to a stop while idling it starts to lag and if i don't give it some gas the engine stalls. i was told that it might be a valve problem but what is the name of the valve?

 

Sounds like your looking for a IAC, Idle Air Controller.

 

if it does it when the truck is warmed up, its the O2 sensor. trust me on this one. they're about $50 at Napa or Autozone. Check the upstream sensors. just replace them.