what is normal manifold vacuum?

[red04fourdoor]

im not having a problem, just wondering. my scanner shows my MAP to be 5.4psi at idle.

[red04fourdoor]

I changed it to metric and got 39-40 kpa
normal?

[petrified.rabbit]

vacuum should not be positive. is that value positive?

[red04fourdoor]

that's the way my scanner reads. I hooked an old style vacuum gauge to it and it was about 14-15 inches of mercury and was in the 'normal' zone. the PO had the timing belt changed about 16,000 miles ago and up until last week it was a tooth off. I changed it back. still had a slight miss at idle but no check engine light. if I block the intake, it dies and there's a hollow sucking sound from within the intake. ive sprayed carb cleaner and propane all around the intake and no change. maybe a leaky valve? still getting over 30mpg so its not affecting much