I have a 305TPI and I have an adj. fuel press. reg. with a gauge. I want to set it around 45psi I think but when the car is running, the needlebounces between 42 and 48psi and yes, I have the vacuum line off and plugged. What is the cause of this? is really fast. I think I have a vacuum leak somewhere else but I dont know what te symptoms are. Please help me ot on ideas. Thanks.