Idling and starting issue

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ahoppj

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I'd recommend you get a vacuum gauge and do your fine tuning. For now you can just bump up your idle speed slightly to get to where you want it.

Basically on the mixture screws I start by bottoming the mixtures screws out and then backing them off 2.5 turns. Start the engine and get it to temp. Then look at the vacuum gauge and adjust in or out until I get the highest vacuum I can on the gauge.
This is assuming your timing is on where you want it. Then after this recheck timing again
Thanks for all the help!!

Can you point me in the direction of where my idle screws are? I’m not even sure what bran carb this is
 

Taylorb27

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Thanks for all the help!!

Can you point me in the direction of where my idle screws are? I’m not even sure what bran carb this is

The carb is a rochester quadrajet, awesome carb. Variable cfm up to 800cfm. Uses what the engine needs with the air flaps above the secondary throttle blades.
The idle mixture screws are on the front of the baseplate on each side. The driver side one is right under your small vacuum line coming out of the front of the carb body and passenger side is underneath the fuel inlet in the same area as the
Drivers side. Depending on year They are going to be a goofy looking head and a flat screwdriver won't work. It's called a double D and you can use a larger tire stem core removal tool, it's what I did.
Your carb looks new enough to have these style mixture screws.

My recommendation though is to just put the pcv back on and your mixtures should be good. Your idle speed lowered when you capped the pcv port on the carb due to the pcv being basically a controlled vacuum leak, idling the engine up.
 

Ricko1966

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I second that, put the pcv valve back.
 

Bextreme04

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In case you didn’t know, the PCV is circulating air through your engine crankcase to clear oil and water vapor. It is using the manifold vacuum to pull the air out of one valve cover and in from the other. You should have a filtered breather on the one valve cover as an inlet and the PCV on the other. This isn’t an “emissions” thing that gets you power when you remove it. It is an engine longevity thing that will help keep condensation and crap from forming in the engine oil passageways.
 

AuroraGirl

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sticking in low and high idle... this sounds like a timing advance curve.

see your distributor cap?
take it and the rotor off under it(inspect them, they are off, look good?)
does your inside look like mine?
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heres mine off a small block buick, 2nd example, and 3-5 are other small block chevy for comparison, the last one i cleaned up, they should look not rusted like that
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