Flooring Tile - Installing 4X4 Kitchen Wall Tile over "old"

I recently removed old porcelain tile on the walls and will be tiling over what remains. What remains is the old adhesive - seems relatively thin but uneven. The underneath is wallboard.

Can I simply put the new adhesive over this surface with the new tile on that?

What kind of tile do people recommend? I'm looking primarily for ease of installation, but I want more than plain porcelain. It is for kitchen walls above the 3" backsplash already installed and below the cabinets - not a lot of tile.

How much old glue is there ? and is it loose and flaking off or really adheared to the wallboard ?

You could use a flat trowel to apply a thin layer of new adhesive to flatten the wall-- let it dry and then install the new tile with fresh adhesive.

Almost all of todays organic adhesives will work fine.

Thanks for the response.

I'd say there is about 60-70% coverage with the old glue. I wire brushed it and put a light coat of primer over it so that we could use the kitchen in the interim. It's not loose or flaking at all. So, I guess your suggestion should work. And if not, you'll see me posting again ;-)

Thanks again!