Im having some problems with an irregularly low idle. When i come to a stop with the trans. still in gear, the engine revs fall to around 500 to as low as 300 rpms, and it has shut off completely once so far. This seems to be a new problem, it hasn't been going on for more than a week or so.
I have a 98 f-150 4x4 with the 4.6 and an auto tranny.
Thanks for any help.

 

Could be an engine control prob..( IAC or mixture prob.) But I wonder if you tourque converter is staying locked up?

 

do a search here on "low idle" &/or "idle problems"

9 times out of 10 it will be your IAC. when the engine is idling low tap the IAC with the handle of a screwdriver and I bet your idle will right itself.