I have 2000 year 2500 series Chevy pickup. it idles at 600 rpm but when driving if I take my foot off the accelerator the rpm drops only to 1300 and stays there coasting to 35 - 40 mph until I begin to apply brakes. Also, when driving and I take my foot off accelerator the rpm drops to 1300 too but if I shift to neutral the rpm drops to 600 like it should. Anyone have an idea of what causes this?

 

You say coasting it is around 1300, but does it go back down to 600 when you come to a complete stop?

 

When you take your foot off the accelerator it stays at 1300 rpm coasting until you apply brakes then as it slows the rpm will drop to 600. If I place it in neutral immediately after starting coasting it will immediately drop to 600 rpm.

 

My '01 has been idling at about 1,000. I'm not sure why. Any suggestions for things to check?

 

im pretty sure that is normal, never really paid attention to it but i wouldnt worry about it, not sure of the reasoning why it does that but i like 99% sure that is normal, unless your rpms are "hanging" then i wouldnt worry about it, i would clean your throttle body though just make sure not to mess up the iac

 

I'll try cleaning the throttle body.....It didn't used to do this so I think something is wrong. It does effect me gas mileage neagtively. Thanks for the advice