Power Valve Blown?
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Power Valve Blown?
I am having an issue with my 750 Holley. (Model 4160)
Idles great, but when you hit the gas, it bogs out, and you have to lift, and feather the gas. Then you can speed up. If you floor it, it doesn't seem like the secondaries are kicking in. Would a blown power valve cause a dead spot at low RPM's? I am new to the world of Holley's, so any help is welcome. I have triple checked the float levels, and the bowl fuel level is right at the bottom edge of the sight window. Fuel mixture is set to where it idles the smoothest. This carb is on a built 400... (.512 lift, 238 duration cam, bored .030, shaved heads & deck, etc...)
Idles great, but when you hit the gas, it bogs out, and you have to lift, and feather the gas. Then you can speed up. If you floor it, it doesn't seem like the secondaries are kicking in. Would a blown power valve cause a dead spot at low RPM's? I am new to the world of Holley's, so any help is welcome. I have triple checked the float levels, and the bowl fuel level is right at the bottom edge of the sight window. Fuel mixture is set to where it idles the smoothest. This carb is on a built 400... (.512 lift, 238 duration cam, bored .030, shaved heads & deck, etc...)
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Joined: Dec 2001
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From: Louisville,Ky.
If the power valve was blown, it would run really rich at an idle, even with the mixture screws all of the way in.
Is the accelerator pump squirting properly? Is the check ball under the accle. pump diaphram in place and free? Is the vacuum advance hooked up properly? Timing correct?
Is the accelerator pump squirting properly? Is the check ball under the accle. pump diaphram in place and free? Is the vacuum advance hooked up properly? Timing correct?
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the accerator pump seems to be working correctly. You work the throttle, and gas comes out of the shooters, at a nice even flow. I haven't put the timing light on it yet, but I think I am going to in the very near future. It idles great, and once you get past the dead spot, it runs great as well. I have the vacuum advance hooked on the outlet off of the metering block, just like Holley says in the book. Could the jets be mis-adjusted? I am scratching my head on this one....
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