Looking for help! 2005 Hummer H2

When I start my H2 and let it idle it will have an erratic idle (needle bobs up and down a bit). It drives great... but when I stop at a light it has an erratic idle again. I thought I’d work on it a bit today. So I picked up some mass air flow sensor cleaner and some throttle body cleaner... some plugs, and new wires. Cleaned and replaced and nothing changed. I had an old car once that did something similar due to dirty IAC (idle air control valve)... but I don’t see one on the Hummer???

It runs good, starts good, just happens sitting at idle.

Thoughts?

 

air/fuel delivery. Air filter clean? Fuel injectors clean?

 

fuel pressure stable? checked the vacuum going to the regulator? air leak in your air cleaner duct? does it do it cold or warm maybe intake gaskets?

 

I checked the filter.. I can see light through it and if I use a vacuum on it it will blow or suck. So I thought it was ok. Plus the cylinder on the air intake shows green while running.

I pulled the TB all the way off and cleaned the heck out of it. It’s spotless for what it is. So I’m ruling that out.

I will fill it up in the morning and dump seafoam in the tank to see if I can clean the injectors.

I got a video too. Once I figure out how to upload it I’ll post it.

 

Also the fuel pump is new this summer... it came loaded so I guess the filter and sensors are fine.

 

 

 

 

 

Another quick check is the pcv valve, remove hose and check the ends for cracking (vacuum leak), then check the pcv if either valve or orifice and clean.