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Edelbrock Pr-Flo setup question

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Apologies in advance for a likely very basic question - I am new and trying to learn. I have a Ford 302 that I installed the Edelbrock Pro-Flo 4 kit on. The engine starts easily and runs fine, but at idle it has a loud hiss. I checked all of the vacuum ports and these are either in use or capped off. I have isolated the noise to the throttle body and noticed that at idle the blades are almost completely closed. There is a screw to adjust on the side, which can open the blades slightly. This reduces the hiss, but also increases the idle fairly substantially. What am I doing wrong?


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Hates: Liver. Loves: Diesel
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You're likely pulling 20" of vacuum past the throttle plates, and your air cleaner isn't blocking any sound. If I take the air cleaner off any of my engines, it hisses like mad. Hissing (even loud hissing) through the throttle is expected.

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Yes I understand and have been able to adjust the idle from the computer. I currently have it set at 650. Is this just too low?
It depends.
I think the procedure goes,
1. Tell the computer what you want your target idle to be.
2. Adjust the curb idle on the throttle body set screw until the motor idles at the desired RPM with a certain amount of IAC opening. I think it is under 20% if I remember correctly.
The less the IAC is open, the less it will hiss.
But remember, until it warms up it's going to hiss while the computer is letting more air in for a high idle.
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