first of all most people mount there fuel pressure gauge on top of the regulator would it give the same reading on top of the fuel filter, the reason i ask is because my car runs much better when the fuel pressure is at 50(with vacuum hose off of course) do you think it would read closer to the spec 40 on top of the regulator. just another thought, when i turn the car off the pressure drops slowly so maybe theres a leak somewhere that would be causing the need of extra fp. also once in a while when i start the car the fuel pressure will go down pretty fast and cause the car to quit. has anybody heard of this and are there any tests i should do.