How much vacuum should my honda have? i hooked up a vacuum gauge, and right now i am getting 5 to 6 hg-in.... first of all what is the measurement hg-in stand for? second did i hook up the tee in the right place? picture is below..
#1 is where the tee is
#2 is what to me seems like a filter
#3 is what i believe is the brake thing which has blanked my mind at the moment

any help/definition/suggestions is greatly appreciated

[IMG]local://upfiles/17154/B98677731B634EA1ABC59C76C2A1288F.jpg[/IMG]

 

What engine do you have?

Are those vacuum lines leading to the (2) brake booster and the (3) check valve?

Hg is the symbol for mercury in the periodic table of elements. A unit of measure for a vacuum is the height (in) that the vacuum can raise a column of mercury (thus, Hg-in). A complete vacuum at atmospheric pressure would cause a mercury column to rise about 30 in. The amount of vacuum in your system probably should increase with engine speed. Perhaps the specs are in the service manual. I know they are listed for the MAP sensor.

 

D16y8

 

depending if you are at sea level or a mile high like i am, people see from 24hg to 17hg at idle. now driving and opening the throttle depending on how much oviesly your vacuum will decrease

 

The line in the picture appears to be for the cruise control. Part #2 is a reservoir and part #3 is a check valve. The larger hose right next to it is for the power brakes. You can tee the gauge into any of the lines leaving the manifold. It appears that you have it connected properly, if that line goes to the same place that the big one for the brakes does.

 

ok so your saying that i have it connected right, so why am i only getting 5 to 6 hg-in at idle?

i don't think its leaking...i listened for a leak couldn't hear much due to loud exhaust ...if it was it would have trouble idling right? what is the normal idle for a civic? also my car is running in safe mode because of an o2 sensor after cat...would that affect performance of vacuum

also another observation when running hard vacuum drops to 0...is this suppose to happen?

thanks guys for helping me on this...

(i live in wisconsin so i believe i am not too high up there)

 

Please read this brief two page article on engine vacuum:

http://autorepair.about.com/cs/troub.../aa112401a.htm

http://autorepair.about.com/cs/troub...a112401a_2.htm

The article states that, at idle, the vacuum reading should be steady and range from 14-22 Hg-in. Therefore, you may have an intake air leak or another problem (see article).

When you increase engine rpm to 3000, the vacuum reading should either remain the same or increase. The fact that vacuum decreases at higher rpm for your engine suggests that it is producing excessive exhaust back pressure (see article).

Reading this article was a learning experience for me. I hope that this information also helps you.