High idle...Only when moving?...

[wishybone2]

Hey Guys

 

I have a 1997 K1500 Silverado factory 5.7 and manual transmission. I have an issue I cant figure out. It idles high when moving. In gear or not... but as soon as you stop its come right down to 900. So the speed senor is obviously telling it to stop. I have changed the IAC and MAF with no luck... it will stay around 2000 to 2500 with no throttle. TP apears to be ok and no check engine lights. Hooked a computer to it and couldnt see anything out of the ordinary.

 

Any ideas?

 

Thanks!

[Holly Elwira Winnie]

Hi, it sounds like you have a problem with your idle air control (IAC) valve or its wiring. The IAC valve is responsible for adjusting the idle speed according to the engine load and speed. If the IAC valve is stuck, dirty, or not getting the correct signal from the computer, it can cause a high idle when moving.

 

tiny fishing

Edited June 16, 2023 by Holly Elwira Winnie