Diagnose Engine Problems w Vac Guage

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HotRodPC

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http://www.secondchancegarage.com/public/186.cfm

Fantastic Link here guys. Everyone with an engine performance issue needs to study this link and all its scnearios.


I'm thinking right off the bat, Iman, hook it up to your engine and lets see what you got going on with that valvetrain and your normal problems. Never know, if anything this info can elimiinate your thoughts of what the problem might be. I still think you have worn valvetrain problems. This can confirm or deny.

http://www.secondchancegarage.com/public/186.cfm
 
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Irishman999

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Curt posted the thing a bunch of times, I will go and get a vacuum gauge in the morning.
 

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This is what I posted a while back, not as detailed but gives you some things to consider...


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89Suburban

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Is this for any motors in any make of vehicle? Including fuel injected?
 

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Is this for any motors in any make of vehicle? Including fuel injected?

This should work for any gasoline engine. Wouldn't work the same for deisel engines.
 

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This should work for any gasoline engine. Wouldn't work the same for deisel engines.

Would PCV port or brake vaccuum line be the place to hook up the gauge? Is there a port on the stock intake of the TBI trucks?
 

HotRodPC

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Would PCV port or brake vaccuum line be the place to hook up the gauge? Is there a port on the stock intake of the TBI trucks?

I would T in a into a smaller port. Maybe one as big as a big nail or size of a pencil. It doesn't really matter which source you use as long as your getting manifold vacuum and not ported vacuum. Into a trans vac modulator line, or egr line would likley be good sources. Of course brake booster is also good too if you have a plastic T or reducer to get the smaller test line onto it.
 

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I would T in a into a smaller port. Maybe one as big as a big nail or size of a pencil. It doesn't really matter which source you use as long as your getting manifold vacuum and not ported vacuum. Into a trans vac modulator line, or egr line would likley be good sources. Of course brake booster is also good too if you have a plastic T or reducer to get the smaller test line onto it.

:waytogo:[
 

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That is a nice link, I like how it shows the action of the guages during each test, I am adding this to my to-do list. :waytogo:
 

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That is alot easier then having to pull spark plugs to check compression, or the gap. Or even to check the timming. Time to get the vacuum gauge out.
 
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oneluckypops

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I didnt have time to look at it all right now BUT some of you may or may not know the CORRECT way to set a Carbeurator is WITH a vacuume gauge.
 

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please remember this reading is correct only with a stock cam and stock timing
 

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I am reading a steady, rock solid 16.5 off the manifold at idle. My gauge I used is in the red says the timing is late?
 

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That would be an easy adjustment to make and see if it brings the vac up. Possible side effect of your bent timing tab?
 

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