High Idle When Cold and in Gear

[Yardsale]

'01, Job 1, 4x4, 178,000 mi.



Started this week. I start it, let it run for a couple of minutes, then "kick it down" a bit to about 1000 RPM. This is a usual. When I put it in gear, the idle raises about 200 RPM. It is fine when at normal running temperature. A/C is off.



I was thinking maybe the thermostat, but that failure is typically high idle all the time.



IAC needs cleaning??

 

[scott degroot]

I would start with a good throttle body cleaning and clean the iac also and see where that gets you. What do you mean by"kick it down"? Are you physically hitting the accelerator pedal to make the idle drop? Kind of like getting the choke to release on a carbuerated engine? What is your outside temperatures at right now when you start it cold?

 

[Yardsale]

I cleaned the TB about a month ago. It wasn't bad.

Are you physically hitting the accelerator pedal to make the idle drop?

Yes. I drops to about 1000 to 1200 RPM. When I put it in gear, the idle raises about 200 RPM. It may do this when warm, but, if so, it's so slight that I don't notice.



This morning, I did nothing and let it run until the idle lowered (to about 800 RPM) and, when I put it in gear, the idle raised a bit (a bit more than to compensate for the load on the engine). Just odd.



Correction on the bad thermostat symptom - the failure is typically high idle all the time once warmed-up.