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Old 01-28-2018, 04:34 PM
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Jack605
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Default Low Vacuum

Running through the steps to tune my engine (350 - 350), I replaced the plugs they were quit dirty and a little wet checked my points and set the dwell with a dwell meter to 30. The next step was to get my idle down around 600 rpm but I cannot get the Holley 4160 below 800 rpm. Pulled out the vacuum gage and connected it up and I was only pulling 10" vacuum (I think it is inches) when I should have been pulling 20". Pulled all the vacuum lines off the carb and capped and I am still only pulling 10" of vacuum. I am headed back out to re-check the dwell on the engine after that I am going to let the engine cool down and due compression tests on each cylinder.

Ideas and thoughts would be appreciated, this is the engine that came with the car and we have not gotten it to run great yet if all the cylinders check out I might pull the intake manifold and re-seat it.

We did have an issue with sending 12lb of pressure to the carburetor but right now I am only getting 4lb of pressure, I might take the pressure regulator off and see what pressures I am getting.

Jack
Old 01-28-2018, 06:11 PM
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Jack605
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Where should the vacuum advance be hooked into? Vac timing port on the carb or full vacuum on the manifold?

Jack
Old 01-28-2018, 09:58 PM
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terry82
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off the manifold.you might not be able to get the idle down because you have a vac leak.

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