Idle problem 98 Z71

[m4]

I have a 98 Z71 that has a low idle when stopped ,600 RPM. How is this controlled? Shawn

 

[throttleissues]

Should have an IAC, idle air controller. Sorry, don't have pic to show you. Should be a small stepper motor with 2 mounting screws into the throttle body. Good chance the port behind it is getting plugged with carbon. IAC might be bad, but not usually. Hope it is that simple for you. Clean it out with sensor-safe carb cleaner.

 

[m4]

I removed the IAC and cleaned the carbon from it. No change. With the truck running I unplugged the IAC no change. Does the IAC open or close to affect the idle? Best bet is probably to scan for codes. Thanks Shawn

 

[throttleissues]

The IAC on Chevy's uses a cone, controlled by a stepper motor, = that pushes in and out of an orifice. Unplugged, it will just no longer adjust the idle speed. That stepper motor may have gone bad. There's also a possibility that the harness has a problem and the signal isn't getting to the IAC. Checking codes might show you some clues to go from. If it does have some fault codes in it, post them up.

 

[noJeepshere]

I have a 98 Z71 that has a low idle when stopped ,600 RPM. How is this controlled? Shawn

My Yukon idles at 600 rpm all the time and it's in perfect running order. If it idles that low when cold, then that's a problem. 600 rpm is where the factory sets it.

 

[thezentree]

Another x2. 600 rpm is normal.