Surging idle after “warm” start

[steelerdude15]

I’ve had an on and off issue for the past few years and I can’t figure out how to fix it. When I start the truck after it has been sitting for an hour or so, I will have a surging idle. It surges 500 RPM between 1000 RPM to 1500 RPM. It will start surging after several seconds and then will level itself out several seconds later. If I put the truck in reverse or drive while it is surging, it will immediately stop. It only does this when the coolant gauge needle is right below the 185F mark. I’ve never had my scan tool plugged in when it does this so I don’t know what the coolant temp actually is. It does not do this every time I start it when it’s warm. It has never done this on a cold or hot start. If I clean the throttle body and MAF sensor, it goes away for a little while and comes back. I have also done a throttle position relearn and it still comes back. I always make sure that the air induction system is on tight. I do not have any stored codes. I do not have any other throttle relates. My truck has the 5.3 and has 58,733 miles on it. I tried uploading a video, but the website says the file is too big. Does anyone know how to fix this or is there a TSB out there regarding the issue?

Edited January 30, 2024 by steelerdude15