I drove for about 30mins, turned of the engine, came back 1hr later and removed fuel filter, I noticed there was no pressure at all in the lines.
Is this normal?

 

All depends, sometimes mine holds all night other times an hour or so. Don't think its a problem unless you can see the fuel pressure gauge actually moving after you shut it off.

 

Some cars depressurize themselves. Its some emissions thing about fuel vapors and what not. older cars keep pressure and the only reason it wouldnt is if it has a leak or the pump is dying. Either of those two would show themselves either in the form of spilled gasoline or the car just running crappy all around.

 

there is no smell of gas while running, I was thinking may be injectors are leaking. And I dont have a fuel press gauge.
I never really had startup issues or bucking at high speeds, but fuel pump is about 210k miles old.

 

If your injectors were leaking from the fuel rail you would know it. If they arent closing all the way, you would be running fairly rich and your car might be hard to start. Basically, as long as your car isnt running visibly rich or lean, dont worry about it.

 

I believe the A32 should hold fuel pressure in the rail for quite a while, not sure for the lines heading to and away from the fuel filter.

 

I have a pressure gauge on mine right now and it holds pressure pretty long after the car is shut off, > 1 hr.

 

^^thats what i thought. Another thing to investigate