Sounds like it could be the idle air control valve, IACV, which is responsible for keeping the idle at the proper RPM when cold like a choke and when hot during engine load from accessories like power steering and A/C, etc. at idle.
Does the truck stall at idle when it is hot when you drive it or when you just start it up in the morning?
I am going to give you a diagnostic walk thorough to help with your situation. When it talks about pulling trouble codes or testing electrical components, Auto Zone or Advance Auto will test and pull codes for free. You will also see metion of tests like fuel pressure which may not be an issue as it sounds liek the IACV neeeds to be replaced, but if you need to run this or other tets both the aforementioned auto stores loan out test kits for alomst anything.Just use the link below to get to the diangostic walk thorugh;
It is an online service manual that is new to customers and I am not sure of access rights o let me know how it goes.
Wednesday, October 17th, 2012 AT 10:02 PM