If there is no pressure at idle, then there is a problem. The minimum acceptable pressure at idle is just under 1 bar.
Which leads me to ask what I forgot to in the first place, what weight of oil are you using? Also, please check the accuracy of the guage first to verify that it is indeed giving the proper readings.
And remember, that sucker should be pegged when the egine is revved.
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record