I seem to have lost the followers on my previous thread re fuel issues so here's the question. I have reason to believe that my fuel pressure regulator is stuck closed. To try and test this I disconnected the return line at the fuel rail and tried blowing through it. I couldn't move air through it using my mouth so I applied approx - 25psi on the vacuum hose after disconnecting it from the throtle body and still could not blow air through the return hose. Does this indicate a malfunctioning regulator or am I totally misunderstanding the operation?