My 5.8L will flash up and idle fine usually first thing in morning but after a 10 minute drive after restarting it idles so low it them stalls. I do have a check engine light on that I need to get checked but does this sound like a throttle position sensor issue. Just looking for suggestions until I get the code scanned.

 

Found a link on how to test the TPS.
With a multimeter I probed the green wire with red lead and grounded the black to battery. With key to on position I opened throttle and it went from .8 to 4.8 smoothly. Seems to be ok?? Link online said probe the black wire which had nothing. Red wire had 12 volts


Part 1 -How to Test the TPS (Ford 5.0L, 5.8L).



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Wire color codes are different for different years so don't worry about that, pull the codes and go from there. BTW.. you don't need any special tools to do this, go to the link and scroll down until you see "how to run a self test" Fuel Injection Technical Library