OK, this one is an odd-ball! When I started my truck this morning, it idled at 2,000 RPMs. When it warmed up, it idled at about 1,000, and had some fluctuation (maybe 100 RPMs) when I was sitting at a light. It ALSO, at the same time, failed to adjust the temperature in the HVAC system. Fortunately, the heat was stuck at about 2/3 or so. The weather here in the KC area has been terrible, so, the heat is appreciated! OK, so I waited until lunch time, and the same issue...I put the truck on my scanner to check fuel trims, etc. I figured it was likely a vacuum leak at the intake manifold, given the fact that the problem got better when the engine was warm. Long Term Fuel Trim was about +1% Short Term about oscillating at about +.8 or so. Normal, so that eliminates vacuum leaks, Evap issues, etc. The O2 sensors were oscillating just fine, the IAC voltage was normal, and the TPS was normal, and worked fine according to the Live Data. I also checked the Intake Air Temp, which was also correct. So, I turned the truck off, put my scanner away, restarted, and it idled perfectly...then the blend door started working correctly.

At this point, I'm writing it off to creepy truck gremlins...or a Demonic possession.

 

I had this one problem when I first got it. It would backfire, almost die but catch itself, and a while list of things. So I shut it down go get my scanner and it says no codes. I thought that too be weird so I went to start the truck to monitor some things and they were all gone. Haven't been back since and that was 2 years ago