I picked up the Hummer from the dealership last night. The tech they flew in installed a new MAF sensor and changed the throttle position. I've put 30 miles on it so far and it hasn't stalled. ::thumbs up!::

If it was the head gasket oil and coolant would mix and be very easy to spot and the rest of your potentials would show up as codes and be pretty easy to diag. She mentions the air flow sensor in another post (and apparently this one now too, lol) and that could be a culprit without tripping a diag code causing it to basically cut of air flow to the engine stalling it out.

No good news. It stalled three times yesterday. The dealership recommended I put a new battery in. We installed a new battery last night. The Hummer stalled again this morning. I brought it right back home and now I'm in my husband's truck. I have a claim into GM's TAC. I'm waiting to hear back on where they want me to take the Hummer. Any recommendations on techs in DFW? I'm feeling helpless and hopeless at this point...

I may have missed it in the posts above but do you kow if they ever re-flashed your computer?

I only found the one I liked and stupid me I didn't get all his contact info just in case. He was at Sewell hummer near the airport, they had just converted over to the Sabb dealership but the hummer techs were still there. I learned more about my ride in the 5 minutes I spent chatting with him than I did from all the service records and the other techs who looked at it. I'm going to be doing more work on my rig at the end of the month and next month so I will keep me eye out. I know it doesn't help you now but sounds like you got very unlucky here with issues way outside the norm.

I had this problem years ago in another vehicle and believe it or not it was the fuel filter.

i would start by seeing if your fuel pressure holds after you cycle the key and if it dont you might have a leaking down injector or regulator .this would give you a hard start problem.also might check all connectors to pcm for bad connctions.

Update: The car is still at the dealership. They hooked it up to some machine yesterday and figured out that the computer that tells the fuel pump when to run is not working properly. They are going to fix that and then let me drive it and see how it goes. Fingers crossed!

Good guess Gunner. Ref lash will probably solve the problem or new ECM.

The jury is still out until Ashley signs off on it......but........

You would have thought that would be the first (most cost effective) thing they did.