Skipping Hummer h2

[cathyiam]

So I posted about the bouncing rpms. Still no reply. I took the Hummer to a private mechanic today and he said that it is probably a coil. The Hummer jumps like it is running out of gas. It does not do it most of the time usually of the morning, but has got to where it does it some in the day- it mostly still only does it around curves but will also do it @ other times. It will do it of the morning and he explained that the humidity in the air of the morning and rain will make it do it worse. Has anyone ever heard of this and does anybody have any different ideas. I have already spent a lot of money on guess work. It does not say "service engine soon' so no code has been pulled. When it jumps the rpms will go up and down, but like I said-it does not do it all the time. I have drove it today and it has not done it at all,but some days it is bad. can someone please help?