Testing while fuel system down

[camron at worldaccessnet.com (Camron D. Crouse)]

Dan Bubb wrote:

(snip)

  Last you probably will
> need to purge any air from the system. You can probably do this just
> by cranking, but while you've got the setup (fuel pump running,
> injectors pointed into some container) you might want to pull the air
> flow plate up for a couple seconds until only fuel comes out of the
> injectors. HTH Dan
> 

Should properly-operating injectors spray "fuel only" or "air/fuel 
aerosol"?  That is, is some air mixed into the spray pattern "within" 
the injector itself, or is 100% of atomizing air supplied by way of 
intake manifold only?

In the airbrush world, there are inferior "external mix" airbrushes 
(with somewhat coarse spray droplets) and there are nicer "internal mix" 
  (air and media mixed within the gun before exiting the nozzle)models 
which produce very fine droplets.  Wondering if there is a fuel injector 
correlation.

- Camron from Vancouver, WA USA
    '86.5 Black 16V 2.0L