correct vacuum?

[95tsiawd_86]

i just installed my boost/vacuum gauge today and was wondering if my vacuum numbers are in spec. i am getting 11-12 inHg at idle and about 21 while decellerating. Acceptable??

 

[Agent Ezzard]

In Florida, those numbers are seen in DSMs with cams. What altitude do you live in? At sea level vacuum is somewhere in the neighborhood of 18-22 inHg

 

[95tsiawd_86]

Omaha, NE: 960-1272ft. above sea level. I also have my gauge tapped into the fuel pressure solenoid hose, ive heard that u can get different reading from different hoses.

 

[1fast97gsx]

mine reads about 17 at idle ( chicago, IL ) ... the line you tapped into is fine.

 

[IMMORTALSPYDER]

Mine is 19-20 in MD

 

[BigBADGSX]

my guess is you might have a little bit of a vac leak....allthough i have most of my lines removed and im right around 10-15(no aftermarket cams)

 

[95tsiawd_86]

would u think replacing all the vacuum lines would correct this? Is there any common place that vacuum can leak from?

 

[DSMeclipse4G63]

check around your intake manifold for cracked old vac lines, and after that start the car and listen and feel for leaks or hissing.
Andrew

ps the only other thing that could be wrong with your car would be bad ignition timing or incorrect valve timing, so to solve that problem if your motor is idling and running fine then its a leak.

 

[sp00ln]

Mine is at 15ish... maybe more on a good day. Im in NV - 4700ft.

 

[blue1]

Mine is around 22 to 24 at idle but thats in Australia, stock VR4 stock cams(manual) and thats about 14,000 miles below you guys. going to try the aussie version of the HKS 272's next week see how i go!

 

[TD05HTalon]

Here's a quick tip for boost gauges that I learned the hard way. After you verify that you don't have any vac leaks check one last thing. Inspect the actual boost gauge line and make sure it's not kinked anywhere. Mine got kinked in my pillar pod and as a result it wouldn't get the right vac or boost signal. When i unkinked it i "mysteriously" gained about 5 psi of boost! It didn't hurt anything that i was running around on nearly 20psi when i thought it was 15 though thanks to my fuel pump though.

by the way - in florida i get about 19-20 on the vac side at idle and near 25 at deceleration.

 

[95tsiawd_86]

its an electrical gauge so i just have a about a foot of the nylon tubing going to an electrical sender.


i am removing the majority of my vac. hoses today, we'll see if that helps, i think it will cuz all the vac. hoses around the intake mani are lookin really bad.

 

[Luke223]

Here in Albuquerque at 5,200 feet, with cams, I am getting 10 inHG while idling and 21 inHG on deceleration. Before the cams, about 17 inHG at idol and the same 21 inHG on deceleration.

Luke

 

[4g63awdtalon]

i am in omaha and on a stock 6 bolt gauge tapped to fp hose i get 18 at idle and it goes to 23 on the way down

 

[sp00ln]

its an electrical gauge so i just have a about a foot of the nylon tubing going to an electrical sender.


i am removing the majority of my vac. hoses today, we'll see if that helps, i think it will cuz all the vac. hoses around the intake mani are lookin really bad.

Let us know what you find and if it made a difference or not.

 

[95tsiawd_86]

i removed the vac. hoses from teh intake mani and capped the 3 nipples, the fps lines are new and a new BOV vac. line and capped the evap. can. port on the turbo inlet. that did nothing. starting to think it might be the timing cuz my idle is also a little off, doesnt seem as smooth aas it should be. i also noticed somethign kinda wierd: in neutral if i hold the rpms steady at about 2000rpm vacuum will be around 18-19, but then right when i let off it will go back to around 12. Could i be right on the timing being a little off???

 

[4g63awdtalon]

did you check the actual line from the gauge to see if it was kinked and also who put in the gauge....

 

[95tsiawd_86]

scroll up and read posts 11 and 12.