Engine Idle at normal operating temperature

[rrb6699]

When I idle my engine at initial startup it idles at normal speed around 1,000 RPMs however, after it warms up and I come to a stop at a street light it goes really low it settles in around 400 RPMs. almost stalls it seems. I'm wondering if that's normal or if there's a way to adjust the idle to make it higher when it is at normal temp. around 1,000 rpms but not confuse the ecm.

tx

 

[Wrnchbndr]

From what I've read, the idle speed and the warm up speed are programmed settings in the pcm. Anything you do is going to cause the pcm to compensate. Nothing short of reprogramming the pcm is going to change your idle.

 

[G-Ride990]

My 5.9 idled around 500 or so. So I don't think yours is abnormal, as long as the RPM doesn't dip below 400 coming to a stop and then come back up to 400. If that were the case I would suspect your IAC might be acting up.

If you are worried about it you could pull the IAC and clean it and the TB ports it sits in. Might help a bit but it certainly won't make it idle around 1k rpm. Why would you want it to idle so high? You will be standing on the brakes at stop lights trying to keep the truck from moving.

 

[dapepper9]

Idle should be 600-800. Try cleaning the IAC on the back of the throttle body with some throttle body or carb cleaner spray. Don't move the pintle. Often times they'll gum up and block airflow a bit