DW is pumping too much water!

[ked]

I have a used DW that is suddenly and consistently pumping too much water into the Air Gap. Lots of water flows into the sink and onto the countertop. At first, I thought it was clogged---but it is a clear passage down into the Disposal. I can even run the kitchen faucet at half open into the air gap with deflector removed, and I can see the water rushing into the disposal. I have created a "Rube Goldberg" rapid flow air gap out of Copper pipe and fittings, two Tees, etc. that still uses the air gap to create a large air bubble in the line from DW to Disposal. Has anybody out there had this problem? Is there a better solution?