Hey guys I just installed my Autometer Boost/Vac guage on my car and had a few questions about the readings it is putting out to see if it is acting normal, since I have never seen or installed a boost/vac gauge before...

1. Upon firing the engine up, the needle goes to approximate 17-20 in. Hg, I am assuming this is normal correct, from what I have researched, that is about correct for the amount of vacuum.

2. While driving, and then letting off the throttle, the vacuum is at about 25 in. Hg, is this correct?

3. When I tap the throttle, the only way the needle goes to zero is if I floor it... if I accelerate slowly, the needle very gradually decreases in the amount of vacuum, but will only go to zero if the throttle is completely open. Any input on this?

Thanks guys I know I probably sound like a huge dumbass but like I said, this is a first for me and I'm trying to see if everything sounds normal. I appreciate the help, thank you!

It's doing exactly what its supposed to.

I second that

make sure you needle sits at 0 when the engine is off also. I bought this autometer gauge off of some dude on ebay and the needle was off by 2 in/hg and I compared it with the one I have now and it was still showing off by 2 in/hg

a vacuum gauge is a good diagnostic tool check you your repair manual to learn what a certain type of reading means. Idle, flutuating needle, etc...

Sounds good, thanks guys I appreciate the input!