express van 2005 5.3 low idle RPMs in cold start

[rury74]

Hi, this is my first post, and my problem is that my chevy express van 2005 5.3 vortec idles low RPM at cold start, about 600 RPM, it doesn,t stall but shakes a little. I have to step in the gas until it warms. Hope you can help me with some ideas.

[txab]

I'd clean the throttle body and MAF for starters

[rury74]

Just cleaned the throttle body and MAF looks clean , the problem continues very low RPM in cold and once the motor its warm works fine, checked the IAC with a special tool that moves it in and out and works fine both sides, somebody told me that, once you remove the IAC an install it again , the computer had to relearn o recalibrate this valve, is there a procedure ?

[txab]

Also check your intake gaskets for leaks

[rury74]

Also check your intake gaskets for leaks

Checked all intake gaskets for any leaks with carb cleaner but it has no leaks at all, also changed the coolant temp sensor, i noticed that the coolant is green, not the orange dex cool, could it be aproblem? does this model have PCV valve, to change it?

[txab]

A 2005 5.3 has a fixed orifice in place of a PCV. It doesn't need to be changed.

 

Have you checked for any codes? What mileage? Any other maintenance been performed, plugs etc...?