There is no air in line Fuel pump pressursizes line and air automatically bleeds from the injector Not enough fuel or pressure will cause rough start
Astro has no AC (cabin) filter.
I have a 2003 astro with the same problem, it was the blower motor
need to install rear heat to my Chevy astro it already have rear air condition
Check the air filter.
no MAP sensor, just mass air flow sensor
A Chevy S-10 doesn't have an emergency air line.
If the air vents of the Chevy trailblazer 2004 are not blowing air, have the fuel pump checked.
Your engine likely has a diaphragm-type mechanical fuel pump. There may be a small crack in the diaphragm that is letting some air into the fuel line. You should replace the fuel pump before it leaves you stranded along the road.
The 1997 Chevrolet Astro Van 02 sensor can be found attached to the outside of the air cleaner housing. The O2 sensor will be on the back side of the air cleaner housing.
To check the pressure the fuel pump creates. You remove the cap, thread the pressure gage on and turn the Key to ON. On a 2003 the range is 48-54 psi
Disconnect the negative battery terminal and remove the fuses pertaining to the air-bag(s)