My 97F150 has the 4.6. I just turned 200K. miles. I notice that the idle does not want to hold occasionally. Sometimes I start it and the idle is fine. Other times I crank it and have to put my foot on the fuel to keep it running. I can drive it for an hour and come to a stop and it dies. I can then recrank it and it idles fine. I am sure it is something electrical. Got any ideas?

 

This is a common problem.

Do a search on 'IAC*' in the Engines Forum.
You need to add the (*) because the search requires four letters.