300TE Fuel Pressure Regulator question. Help!

[Ron Johnstone]

Sorry to ask dumb questions, but my CD Rom has seemingly outdated information and non exact part diagrams of the Fuel Pressure Reg.
I have p/n 0 438 161 001, in my '88 300TE. Blowing into the center orfice with my mouth, I get no flow. Blowing or sucking on the opposite, vacuum end , there is also no flow. But, blowing into either of the side orfices, there is a definite, slight air flow.

The diagram, such as it is, seemingly shows that there should be no flow.

Would, or can anyone confirm this?

Assuming that I have a leak between chambers, this would account for the fact that the car won't start for lack of gasoline to the cylinders and that I should replace the regulator. Actually, I'v already replaced everything else between it and the gas tank.