Thread: vacuum pressure

Originally Posted by Liquifire

so you want lower vac at idle or what? I know max boost is not a good thing to go by because that only tells you how much resistance that you have getting the air out of your pump(motor/exhaust) so 8 pounds just means you are getting it out well. You may have a vacuum leak and if so check as stated above. Has it been this way for a long time? do you have a way to scan for it at all times? have you changed any parts recently or done any work which may have effected this? Checked brake booster?

Well since lower vac seems to be the norm, yes i would like it lower. I am not even on the high end of the norm (-15 or so i have read).

Yea i figured boost wasn't a great way to tell if the gauge is working. I have no way of knowing how long it has been like that. I just installed my gauges on Saturday, the boost gauge is used so their is a slight possibility of an issue.

The scanner i have does not read out boost unless i have missed it somewhere.

I recently put in a DP, i don't think this could affect VAC could it? There are no exhaust leaks.

No haven't checked the brake booster, honestly i don't even know what that does (i kno where it is though). Ill have to google it.

I dont think that the DP could affect the vacuum........just would possible affect how much boost you have at the high end........I think the brake booster is just that. It(through vacuum) assists your brakes so that they are not manual. If you dont have enough vacuum(through a leak or through something like a large cam) your brake assist will not help you as much or at all....This is just the largest vacuum line and that is where I would start. Do the spraying carb cleaner trick all over any vacuum lines and fittings.........Hope this helps some.....