Idle Vacuum readings

[dgoodhue]

What is a normal for idle vacuum, I usually get 20". I know this sounds like a stupid question, but I just found out my other car has low vacuum which I hope has been a root of its problems.

 

[Falco]

I can get around 18-19"...

Later,

 

[sytyguy]

Even with the 412 cam I get good vac readings. Here are some examples:

Idle (P/N - 800rpm)- 18"
60mph (OD - 1800 rpm) - 15"
70mph (OD - 2000 rpm) - 12"
80mph (OD - 2200 rpm) - 10"

Vac should be rock steady at idle.

HTHs

Michael

 

[MR_MNZTR_SY]

yeah i get right around 18-20.

when do you get low vacuum? when your boosting? :drinking:

 

[kwick6]

right around 21-22" @ idle with a stock motor, and 136K miles.

 

[InvisiBill]

 

[MR_MNZTR_SY]

heeheehee thats certainly one way of answering! :lol:

 

[White97SVT]

I get 20 at idle. Then when i am on the highway rolling along at 70 if back off the gas it will read like 24-25. How come you get more vacum when you are on the highway at like 70 and let off.

I get less though when i am just riding around on the highway with cruise control at about 70. What do you guys get when you are ridding around at about 70 or so.

 

[Lynn D. Brown]

White - U said :
How come you get more vacum when you are on the highway at like 70 and let off.

Because U have closed the throttle plate and R seeing the full Vac of the engine. The more U open ther throttle, conversely, the lower the Vac gets, because U R letting in air and Fuel to "fill" the Vacuum.