Vacuum at idle

Mixedbreed · Jan 8, 2014

I moved to Wyoming a week ago. So I notice the air is thinner and it way colder then Vegas. But I also see that I pull 2.7 - 3.3 pounds of vacuum at idle. (Lower end if that when warm at idle)Is that normal? Truck is a little more laggy but I expected that. Is that much vacuum normal? I used to see .6 vacuum tops at idle in Vegas.
Here is a pic of my liverwire.

jngreen · Jan 9, 2014

I doubt that you are actually pulling vacuum, I bet the gauge is calculating boost by subtracting normal atmospheric pressure, which is something like 14.7 psi at sea level. Since there is less air in higher elevations, subtracting by 14.7 actually puts your gauge further into thr negative numbers.

WYO7.3 · Jan 9, 2014

What part of Wyoming did you move to?

Mixedbreed · Jan 9, 2014

jngreen said:
I doubt that you are actually pulling vacuum, I bet the gauge is calculating boost by subtracting normal atmospheric pressure, which is something like 14.7 psi at sea level. Since there is less air in higher elevations, subtracting by 14.7 actually puts your gauge further into thr negative numbers.

hmmm

WYO7.3 said:
What part of Wyoming did you move to?

yours.

WYO7.3 · Jan 9, 2014

Mixedbreed said:
yours.

My fiancé lives in Laramie. I'm up in lander right now working but I spend a ton if time down in Laramie we aught to meet up and shoot the sh!t.

WYO7.3 · Jan 9, 2014

jngreen said:
I doubt that you are actually pulling vacuum, I bet the gauge is calculating boost by subtracting normal atmospheric pressure, which is something like 14.7 psi at sea level. Since there is less air in higher elevations, subtracting by 14.7 actually puts your gauge further into thr negative numbers.

I would agree diesels are usually pressurized with little to no vacuum at set times. Hence the use of vacuum pumps.

Mixedbreed · Jan 9, 2014

So is there a fix? And yeah. Let me know when your in town man.

jngreen · Jan 10, 2014

What does your monitor read with your key on, engine off? Does it read zero?

Mixedbreed · Jan 10, 2014

jngreen said:
What does your monitor read with your key on, engine off? Does it read zero?

Ok. Good idea to look. Reads 3. So it's reading it all the time. I reloaded the tune and it still does it. I am trying to figure out if this is normal.