Odd idle redux - idle increase when temps outside are cooler

[Orionsbelt]

Ok, now that I've had this truck through a few seasons I can make some observations.

I noticed this summer (Calgary) on hot days that the usual "idle creep" I was getting during cooler/cold days stopped. Or rarely occurred. Now that it's getting cooler, it's starting to come back.

The odd thing is if I get the truck to operating temp then shut it down for a bit ... 1 hr + ... then go back it won't creep. This occurs without the heater or air on/off.

Anyone with any ideas..? Is there some temp something to adjust?

Thanks, Orion

[mararmeisto]

What you identify as "idle creep" - do you mean you have to re-adjust your idle set point on the throttle body? Or are you talking about how your engine revs a little higher when cold than once warmed up?

Could one of the proper mechanics chime in at this point, please.

[Orionsbelt]

I'll clarify.

I've got the idle set around 600 or so. It actually idles low when approaching operating temp (hard to say where it starts to creep) BUT as it approaches operating temp the idle starts to creep up to 900-1000.

When at stop lights I typically throw it into neutral which is how I watch/notice it.

Keep in mind it barely ever, if ever, did this during the heat of the summer - operating temperature or otherwise.

So what's the connect between the cooler exterior temps and the idle? And I don't think it's the throttle cable sticking or anything like that.

Thanks, Orion