[dvldoc]

First I would relocate the IAT further down or mount the nozzle before it if you want the computer to see the temp change. But it actually looks like you have more than enough space to mount the nozzle right before the IAT sensor , It does not have to be across from it just before it the spray patter is pretty big inside a pipe at 150 plus psi.

When you check for voltage make sure you have the Key in the ignition on position. Or with the vehicle started.

You should be getting a 5v to 4.5 volt reading from one wire which would be the power wire to your sensor, One should be a ground and the other should be the 5 volt output which should be reading around 1.35v or close to that at idle that is the wire you should be using. The voltage readings should not be that low.

Some voltmeters take a few seconds to pick up the voltage fully so let it stay connected for a few seconds.