I recently found that I have no pressure or suction in the PCV line... Neither from the throttle body nor from the valve cover... What could be wrong and how do I fix it...

 

The way you are checking it. Does the intake port pull any vacuum? Or are you checking the hose?
The extra crankcase vent going to throttle body did you raise the toms to see if it's pulling vacuum? No vacuum means the crancase is building severe pressure and gases and can do severe damage to your motor

 

i think you are checking the air intake side (passenger side of motor)of the pvc system. the pcv valve is on the driver side of the intake manifold, about half way.

http://shbox.com/1/pcv.jpg

http://shbox.com/1/pcv_pipe.jpg

 

yes, I did check on the passenger side... Should their not be any pressure on that side...

 

right no pressure on that line. thats where the air comes in that gets sucked into the intake on the other side of the motor. so i guess if you plugged the valve cover side long enough it would creat a suction. well thats if you have the dip stick sealed good and none of the gaskets or seals are shot.