Paint dries right out airbrush . . .

I'm fairly new to airbrushing and have a question:

I use mostly acrylic paints, thinned with water or Windex, in my Iwata Eclipse airbrush. And when I shoot the thinned paint through the airbrush it paint appears on my models as tiny little strings, already dry.!.

My friends tell me the paint is actually drying as it's shot from the nozzle and is landing, dry, on my models giving it a rough texture.

Is there something else I should be mixing with my acrylic paints to prevent them from drying too fast?

When I use ready made paints such as ComArt my airbrush works fantaskticly. But when I cut my acrylics with water or Windex (1:1) they come out... well, glopy. I use a Squadron paint mixer so I know the paints are thoroughly incorporated.

thanks for your help
Mark Fannin