What fuel line did you pull off?
If it was the return line to the tank you do not expect much fuel.
May be a wiring problem where the leads going to the injector have a bad connection or are shorting to chassis/ground.
You need to download the 2006 Jeep KJ Service Manuals from here:
Manuals:
http://www.colorado4wheel.com/manuals/Jeep/KJThe manuals will tell you how to check out the injectors...each injector has its own parameters on it for maximum performance so it is best to put injectors back in their original position.
Section 8W has the Wiring Diagrams but first dis-connect the battery and re-plug the connectors on the ECM a few times in case of a bad contact before climbing into the wiring!
The 2006 CRD has a known problem whereby the Fuel Filter Head Mounting Bracket can damage the wire harness behind it causing shorts to chassis so it is worth looking in that area for wire damage.