The other day after an hour long drive my truck all of a sudden started surging under part throttle usually from a stop or low speed. It seems to start doing it after 10-20 minutes of driving. The motor is only around a year old since my build and has been running perfect untill now. Other than the surging the truck runs normal. I checked the fuel pressure while idling and it looks normal (I also have a inline walbro pump) and I replaced the fuel filter since I had a spare on hand and within the last 6K miles I have replaced the spark plugs, upstream 02 sensors, throttle position sensor, IAC, cleaned the MAF and throttle body.

Here's a short video (must click on it to view) I took of it doing it. sometimes it will surge a little and other times it will do it quite a bit like in the video.

--Any ideas of what to look at next would be appreciated!
--Truck specs are in my sig.

 

Still doing it. Not as much now that the weather has gotten colder. Anyone have any ideas?