Thread: 350 running rich

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You're using ported vacuum, unplug your vacuum advance and plug the gauge in there.
https://documents.holley.com/199r11202.pdf
https://documents.holley.com/199r10014rev1.pdf

The PV (power valve/enrichment valve), if its diaphragm and gasket are sealing (verified by installing new one), will not add fuel to the idle circuit even if opened as it feeds fuel through the venturi boosters and operates off venturi vacuum, manifold vacuum only controls when it opens.

The carb is idling way too rich, the idle circuit is not fed by the jets in this carb design. While jetting is absolutely going to need adjustments, IMHO, first up should be getting the idle circuit under control.

The OP just gave us a clue that he did not buy this carb new or he would know more about it. It is possible the carb has been fiddled with by others and the idle feed restrictor may need changing.
https://www.musclecardiy.com/perform...bration-guide/

JMHO, Once we get the idle/transition circuit under control we can move on to further tuning the carb.

Originally Posted by 36 sedan

You're using ported vacuum, unplug your vacuum advance and plug the gauge in there.
https://documents.holley.com/199r11202.pdf
https://documents.holley.com/199r10014rev1.pdf

Just to be clear, I'm currently using the port that I have circled in red, would that be the correct one? Or should I use the one that I have the vacuum advance plugged into, which is the one directly to the left of the one I circled?

Originally Posted by DennyW

I see now. You have your vacuum gauge on a ported port. That's why it only shows " vacuum on the gauge.
You have to find a full vacuum port for the vacuum gauge.


Attachment 72684


Attachment 72685


Attachment 72686


If you are running the normal Chevy Style where it uses full vacuum at idle, then you have to use the right port depending on your setup...


Descent video...

Quick Fuel Technology Carb Install and Tuning Walkthrough- RODDING REVOLUTIONS ISSUE #1
https://www.youtube.com/watch?v=70hhpX2tfsE

The 3rd pic you posted is where I should be plugging in the vacuum advance then, correct? Right now that port has a plug over it.