Hi there guys
I am writing this because I am at a loss. I would like to preface this by saying I am NOT a mechanic but do have some average knowledge of how a motor works and the mechanics involved. My father in law helped me build this and he was an old gear head from way back, but he has since pasted on so I am turning to other professionals, like you for help. I am also not looking to start any wars or have any smart ass answers or someone make fun of me or run their mouth like I have seen before.
With that being said...
I am trying to tune my flatbottom for the summer and need some words of encouragement.
Chevy 454 .30 over
Big Cam in it
Holley 750 with a vacuum secondary
Edelbrock intake manifold
A few years back this thing ran like a top. The problem that I am having is it will start just fine, and once it is warm it will stay running; however the motor idles extremely rough and at about 1500 rpm(s) I have backed the idle mixture screws way out (probably to far)The curb idle screw is all the way down, but if I back it off the motor will die. When it is idling at that 1500 rpm(s) it will surge to 2000 rpm(s) and then back down and sometimes dip to 1100 rpm(s) or so. I have adjusted the float and the accelerator pump work just fine, in fact it has no hesitation or any lag when you give it some gas. I dont think I have any type of vacuum leak or anything like that. I believe it is solely in the way the carb is set up right now.
I know that there is something that I am missing and I know it is most likely a very small issue, I just want to solve this issue.
Any suggestions to set the idle at about 1100 rpm(s) and have a good idle without the surge?
Any suggestion will help!
Let me know if you have any questions or need any more information on the motor.
Thanks for your time and advice!!!