I have a question for the tuner guys out there. If I apply 10 hg of vacuum to the fuel regulator with a hand vacuum pump, should it hold at 10 hg if the diapham is good? Or will it just drop off. I have an adjustable regulator on it, and when you first start the car, it is fine. I adjusted the regulator to 40 psi at idle. But, when I shut the car off, the pressure shoots up th 46 psi, and the car has a little problem starting again. It will start, but stumbles around and blows out black smoke for a minute. I can rev it up and it clears out, but that is kind of embarrassing at shows. I applied 10 hg of vacuum with my hand vacuum pump, and the pressure does drop down about 4 psi, but the vacuum bleeds off pretty fast. Is that normal, or should the vacuum hold. Could there be a hole in the diaphram that is causing the wrong readings. I had to turn my regulator up pretty far to get the pressure to move at all. Any help would be appreciated.