Vacuum operated devices
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Vacuum operated devices
As many of you know, modern cars in general, and our EX's in particular, use manifold vacuum to power a number of devices.
In the old days, fuel pumps typically had a 2nd chamber to generate vacuum when the engine was under enough load to reduce vacuum.
All of my vacuum-powered devices work fine. ALL of the time EXCEPT for the following:
And here's why I never noticed this before on my '05 EX V-10 4wd - dont normally run at higher throttle settings (nope, not even when pulling heavy loads)
On a long LONG up-hill grade on the Interstate, my air conditioner "defaulted" to "defroster" mode. Soon as I backed off the gas, it went right back to normal operation. Obviously, ran out of vacuum.
Since everything SEEMS to be working just fine, and I dont see any OBVIOUS vacuum leaks, I am HOPING there is nothing wrong.
What about it - guys - do our EX's have some kind of "back-up" vacuum pump to supply engine vacuum to vacuum-controled devices ? If so, does this suggest the thing is failing, and where IS the little devil, anyway ?
Or is this just normal ?
In the old days, fuel pumps typically had a 2nd chamber to generate vacuum when the engine was under enough load to reduce vacuum.
All of my vacuum-powered devices work fine. ALL of the time EXCEPT for the following:
And here's why I never noticed this before on my '05 EX V-10 4wd - dont normally run at higher throttle settings (nope, not even when pulling heavy loads)
On a long LONG up-hill grade on the Interstate, my air conditioner "defaulted" to "defroster" mode. Soon as I backed off the gas, it went right back to normal operation. Obviously, ran out of vacuum.
Since everything SEEMS to be working just fine, and I dont see any OBVIOUS vacuum leaks, I am HOPING there is nothing wrong.
What about it - guys - do our EX's have some kind of "back-up" vacuum pump to supply engine vacuum to vacuum-controled devices ? If so, does this suggest the thing is failing, and where IS the little devil, anyway ?
Or is this just normal ?
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xjcamaro89
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Feb 13, 2026 05:07 AM
