[SteveK2003]

If you're not getting anything coming out, there must be a cog someplace, or the nozzle isn't installed properly. It could also be a leak in the airline, either where it mates to the air supply or in the hose itself: If had that drop pressure from the can so much that it would barely shoot paint.

You may have thinned the Tamiya paint with the wrong medium: Always use Tamiya thinner or 90% isopropyl alcohol. Other kinds of thinners can cause the paint to get lumpy and also clog the airbrush (This happened to me as well, using enamel thinner with Pactra's lacquer R/C paint).

Worst-case is that you send the airbrush to Testors and they send you a new one.