high idle rpms till truck warms up

What could be causing this....I have a 2000 3.4l 4x4 with 5 speed tranny that runs about 1500rpms after starting and will idle there till the truck warms after driving for several minutes. After it warms it sits around 1000rpms. I know often times after I drive awhile and then run in an out somewhere and try and start it back up if I don't let the starter cycle enough then the engine is tough to start for a little while. Maybe I am running too rich but have no idea if that is even stuff you can adjust.... the truck runs well I just guess it has me confused yet again

 

when cold there is a solenoid that holds the throttle body open to fast idle so the truck can warm up and not stall.

the engine coolant runs through a vacuum switch that turns it off when the truck warms up.

it may need adjusting but it should be idling around 1200 when cold so see what the manual says your engine should run at when cold

 

Which part would need the adjusting?

 

located your IAC, idle air controller, and try cleaning out all the gunk.

 

Mine has done that since new... It's a V6 Auto and when I start it up in the morning (and lately it been a bit chilly in TX) it will idle at just over 1500 rpm until about 110-120 degrees according to the UltraGauge. Then it will slowly step down until finally the idle sits at about 600 or 700 when in Drive.

--Dan

 

well there you go, seams like its working as it should then

I know my 4 banger idles at 1200 rpm when cold and 650 after its fully warmed up.