Unsteady vacuum. Start-up one day and I pull 18 Hg, yesterday I only 14. Today 17!
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From: Bayville NJ and Newark at NJIT.
Unsteady vacuum. Start-up one day and I pull 18 Hg, yesterday I only 14. Today 17!
What gives, what should I look for... A vacuum leak affected by humidity? Or heat? Most of the hoses are new and sealed well. The others don't look bad, what pieces could be bad. Is this related to my lack of working CC?
Throw something at me... engine performance seems to play a hand around this...
Throw something at me... engine performance seems to play a hand around this...
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From: Philly, PA
Damon
Vacuum is not a constant thing. It will vary DRASTICALLY depending on RPM and throttle postion. Changes from hot to cold will also play with it some. If it runs OK, forget it and move on with life.
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From: Valley of the Sun
Car: 82 Z28
Engine: Al LT1 headed LG4 305
Transmission: TH350
Axle/Gears: 3.73 posi with spacer
Why are you so worried? Does it not run right? If it is fine i would not worry about it unless the vacuum fluctuates!
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From: Bayville NJ and Newark at NJIT.
Originally posted by RJR99SS
yeah, just as a general rule: vacuum at idle is going to be somewhere between 15-22
yeah, just as a general rule: vacuum at idle is going to be somewhere between 15-22
Crap, I hate when that happends...
Back to the drawing board.
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Joined: Jan 2002
Posts: 3,852
Likes: 1
From: Valley of the Sun
Car: 82 Z28
Engine: Al LT1 headed LG4 305
Transmission: TH350
Axle/Gears: 3.73 posi with spacer
How much vacuum you have at idle depends on several different factors, such as cam, intake, carb, and ring seal. A vacuum of 14 is not low, 8 is pretty low.
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